#12Q 2023 Financial Results BIGCOMMERCE#2B Disclaimer This presentation has been prepared by BigCommerce Holdings, Inc. ("we," "us," "our," "BigCommerce" or the "Company"). This presentation may contain forward-looking statements which constitute the views of the Company with respect to future events which can be identified by the use of forward-looking terminology such as "anticipate," "believe," "budget," "can," "continue," "commit," "control," "could," "estimate," "expect," "intend," "may," "ongoing," "plan," "potential," "predict," "project," "should," "will," "target" and similar words or phrases. These forward-looking statements include statements concerning the following: the impact of the COVID-19 pandemic and the associated economic uncertainty on the Company, our customers, and our partners, and our response thereto; our expectations regarding our revenue, expenses, sales, and operations; anticipated trends and challenges in our business and the markets in which we operate; our ability to compete in our industry and innovation by our competitors; our ability to anticipate market needs or develop new or enhanced services to meet those needs; our ability to manage growth and to expand our infrastructure; our ability to establish and maintain intellectual property rights; our ability to manage expansion into international markets and new industries; our ability to hire and retain key personnel; our ability to successfully identify, manage, and integrate any existing and potential acquisitions; our ability to adapt to emerging regulatory developments, technological changes, and cybersecurity needs; and our anticipated cash needs and our estimates regarding our capital requirements and our need for additional financing; and such other risks and uncertainties described more fully in our documents filed with or furnished to Securities and Exchange Commission, including our Annual Report on Form 10-K for the year ended December 31, 2022 as filed with the SEC on March 1, 2023, our Quarterly Report on Form 10-Q filed with the SEC on August 4, 2023 and the future annual, quarterly and current reports that we file with the SEC. The statements are made based upon management's beliefs and assumptions and on information available to management as of the date of this presentation. Forward-looking statements involve both known and unknown risks, and there is no assurance that such statements are correct or will prove, with the passage of time, to be correct. Actual events, results, achievements or performance may differ materially from those reflected, implied or contemplated by such forward looking statements. All forward-looking statements attributable to us are expressly qualified by these cautionary statements. Any past performance information presented herein is not a guarantee or indication of future results and should not be relied upon for such reason. The information contained herein may change at any time without notice, and we undertake no duty to update this information except as required by law. This presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such data and estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk. Neither we nor our affiliates, advisors or representatives makes any representation as to the accuracy or completeness of that data or undertake to update such data after the date of this presentation. In addition to financial information prepared in accordance with generally accepted accounting principles in the United States ("GAAP"), we use certain non-GAAP financial measures to clarify and enhance our understanding, and aid in the period-to-period comparison, of our performance. We believe that these non-GAAP financial measures provide supplemental information that is meaningful when assessing our operating performance because they exclude the impact of certain amounts that our management and board of directors do not consider part of core operating results when assessing our operational performance, allocating resources, preparing annual budgets, and determining compensation. The non-GAAP measures have limitations, including that they may not be directly comparable to other companies, and you should not consider them in isolation or as a substitute for or superior to our GAAP financial information. See the Appendix to this presentation for a reconciliation of non-GAAP financial measures to their nearest GAAP equivalent. 2#3Who is BigCommerce#4BCompany overview BigCommerce is the Open SaaS platform for all stages of ecommerce growth ▸ BigCommerce is the premier open SaaS and composable platform for ecommerce ▸ We enable merchants to run best-of-breed technology solutions without friction ▸ We're growing enterprise rapidly ▸ We're the leader in omnichannel selling, helping merchants boost sales regardless of their size or existing platform Gillette W LIMITED TIME OFFER electrostate with a Poo Prote ProGlide Shield FREE Sef Cont $22 812 ADD TO CART GET STARTED PRODUCTS SHAVING TIPS Get everything you need to start looking and feeling your best when you subscribe to your favorite razor THERE'S A BEST FOR EVERY MAN. BADGLEY MISCHKA 5 Skullcandy berlin PACKAGING SHOP NOW ABOUT GIFTS LIMITED TIME OFFER: Receive a free travel case with any ProGlide or ProGlide Shield purchase solo stove LONDON Gillette TED BAKER NATORI ScJohnson MOLTON BROWN LONDON How It Works Leica Login a 1- UPLIFT DESK PETER CHRISTIAN#5B Company overview BigCommerce at 6/30/23 $331M ARR +12% 2Q23 | +41% 2Q22 +38% 2Q21 $ Durable revenue growth +11% 2Q23 | +39% 2Q22 +27% 2022 | +44% 2021 +14% enterprise account ARR growth ㅏ ~t 77% Q2'23 non-GAAP gross margin $- Customer Target Segments Enterprise Mid-market target: $1M-$50M GMV Large enterprise target: $50M+ 71% of account ARR Non-enterprise SMB target: <$1M GMV 29% of account ARR Note: All statistics as of 6/30/2023 unless otherwise noted and include impact of the acquisition of Feedonomics. $236M Enterprise ARR 71% of total $331M ARR $39,870 enterprise account ARPA +5% 2Q23 | +22% 2Q22 5,929 enterprise accounts +9% 2Q23 | +38% 2Q22 Q2'23 new store launches Including... Barbecues Galore, an Australian merchant selling grills, grilling accessories and outdoor furniture. Square Enix launched multiple new stores to power their multi-language and multi-currency needs. Rogers Sporting Goods launched a new B2C site using our native Stencil framework. Francesca's, a popular women's clothing brand, is taking advantage of BC's Page Builder tool combined with a customized theme and customized checkout. 31 5#6B BigCommerce Enterprise accounts "Enterprise accounts” have at least one contracted enterprise plan. These accounts include mid market customers with $1M-50M per year in GMV to enterprise customers with greater than $50M per year in GMV Enterprise accounts: (a) may require complex product feature sets (b) look for custom-negotiated, multi-year contracts (c) want technical and professional services offerings (d) include merchants in both mid market and enterprise segments#7B BigCommerce enterprise accounts @ IPO vs today Enterprise accounts Mid-market target: $1-50M GMV Large enterprise target: $50M+ GMV Non-enterprise accounts SMB target: <$1M GMV $90M Note: statistics as of 6/30/23 $77M 3Q20 (IPO) Enterprise account ARR Retail account ARR 54% of account ARR Average revenue per enterprise account: $28,370 46% of account ARR $236M $95M 2Q23 71% of account ARR Average revenue per enterprise account: $39,870 29% of account ARR BigCommerce's enterprise business has grown rapidly in the brief time since IPO, driven by our key business strategy: disrupting legacy enterprise ecommerce.#8FINANCIALS Investing to win in the mid market and enterprise segments to drive Enterprise ARR growth +32% +37% +41% +44% +46% +44% +41% YOY $35 $38 $42 $46 $51 $55 $61 +44% Note: growth rates represent organic + inorganic growth +40% $67 $71 IPO +48% +44% $80 $90 +51% $101 +58% $112 +54% $123 +78% $160 +72% $173 +68% *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition $189 +68% $207 +35% $216 1Q18 2018 3Q18 4Q18 1Q19 2Q19 3Q19 4Q19 1Q20 2Q20 3Q20 4Q20 1Q21 2Q21 3Q21 4Q21 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 +14% +30% +21% $236 $224 $229#9The market BigCommerce serves#10B FINANCIALS Global ecommerce momentum continues to accelerate and gain long-term share over brick and mortar Adoption of ecommerce is accelerating 19% 19% $5,920 $5,437 $5,075 il 20% 2021 2022 Retail ecommerce spend ($bil) 2023 21% $6,478 22% $7,046 23% Sources: eMarketer, Dec 2022; Morgan Stanley Research; William Blair Research $7,619 2024 2025 2026 Retail ecommerce (% of global retail spend) Many enterprises use 'monolithic' legacy ecommerce platforms that need to be replaced for more modern and flexible architecture Headless and composable commerce architecture makes implementing new ecommerce software for B2C and B2B merchants easier than the old rip-and-replace model#11BAddressable market: platform spend BigCommerce serves B2C and B2B merchants all on one platform Ecommerce platform spend forecasted to grow to $16.5B in 2027 Worldwide digital commerce applications revenue by deployment ($Bn) 8.6 9.8 11.2 12.8 14.6 16.5 19% CAGR 2022A 2023E 2025E 2024E 2026E 2027E ■On-premise/other software ■ Public cloud services (own IP) Source: IDC Worldwide Digital Commerce Applications Revenue Snapshot, May 2023 (1%) CAGR 4 Enterprises are choosing Cloud/SaaS over on-premise software 4 BigCommerce uniquely combines the flexibility of open-source with API-first composability and the benefits of multi-tenant SaaS B2B application revenue spend is growing faster than B2C, and BigCommerce enables merchants to run B2B and B2B or a hybrid version on one platform 11#12BAddressable market: platform spend + digital marketing + major PSR components Addressable market expanding beyond platform spending $28BN TAM $BN TAM 30 25 20 15 10 5 0 2021E 2022E 2023E 2024E 2025E Payments Gross Margins¹ 95%+ 100% 75% ■ Platform ■ Digital marketing / Omni ■Apps Shipping Note:¹ Gross margins represent BIGC estimates based on net revenue recognition on PSR Sources and assumptions: (1) Tech platform spending based on IDC Worldwide Digital Commerce Applications Revenue Snapshot, 2021; (2) Digital marketing / Omnichannel spending based on eMarketer, March 2021, assuming US ecommerce ad spending is approximately 50% of global, with 2% addressable by BIGC through Feedonomics; (3) App TAM assumed to be equal to tech platform spending reflecting potential BIGC 20% revenue share; (4) Shipping and payments spending based on Grand View Research market size studies from May and June 2021; assuming 2% and 10% addressable, respectively. 12#13The BigCommerce go to market strategy#14B Growth strategy BigCommerce Strategic Focus STRATEGIC INITIATIVES STRATEGY PILLARS # Enterprise International Omnichannel Open SaaS Disruptive Tech A B2B Composable Commerce- as-a-Service 14#15BOMNICHANNEL Merchants want to be able to sell more everywhere. G 4 4 4 Accelerate growth by easily listing products across social channels, marketplaces, search engines and new regions. Drive channel performance through accurate and optimized listings. Elevate customer experience through consistent listings, up-to-date inventory levels and automated order syncing for fast fulfillment. Increase operational efficiency with a combination of automated and managed services. TED BAKER LONDON PUMA SONOS ♥CVS Health. * ebay amazon More GMV 3 Better customer experience Higher conversion Improved data and listings B 100+ ad, social, and marketplace channels More traffic f Increased views and ROAS O All trademarks and logos are the property of their respective owners (o 8#16B2B buyers across industries expect a modern experience similar to what B they see in consumer-focused ecommerce Publishing, Printing, IT & Electronics Industrial & Ag Supply Food, Beverage & CBD Healthcare, Medical & Safety Supply Apparel, Sports & Outdoors Manufacturing Homegoods & Building Supply Harvard Business Publishing Corporate Learning FARMER BOY ckfoods eneration Food Cont amtouch DENTAL SUPPLY KELTY berlin PACKAGING USCutter sherrilltree ML XGREEN ROADS SIEMENS Healthineers MANN LAKE BEE & AG SUPPLY Black Diamond Odiono TECTRAN Driven to be BETTER Lifetime Brands A UNITED suppliesoutlet, BEEF SWEET SQUARED T Rainbow ECOScience NATORI ascdirect.co.uk THE ON-LINE PACKAGING COMPANY BARRON DESIGNS CANDY CLUB EMPIRE Moulding & Millwork AMIVD Bug Products Company AFFINITECH 2 HANNA instruments Clarion Safety Systems GIRL & DUG SAN DIEGO I PORTLAND UDSON ASTENER SONERSTEDERS.com 1-877-4-A-SCREW THE S SILK WORLDWIDE FUJITSU DE ELECTRONICS ATS Advanced Technology Services, Inc. WALTON'S Everything but the Meat. PREMIER SAFETY VA K9 GZS TOBEN HSWHOLESALE UFACTURING JUUL MASTER DISTRIBUTOR GILDAN Orangetheory BRANDS AORN SAFE SURGERY TOGETHER COOK&BOARDMAN MKM BOXHUB. psi ACLS DuraMark Technologies panache The Chas. E. Phipps Company#17B Strategic Initiative Composable for enterprise ecommerce seeking the most modern approach to technology For enterprise customers, now more than ever, flexibility and composability are especially important: freedom to mix, match and combine best of breed tech solutions to create a more customized and robust technology stack. B2C and B2B merchants can now create the most modern customer experiences and enterprise grade solutions without limitations or complexity. MKM Mountain Equipment Company MACHL ALLIANCE Kōkatat TED BAKER LONDON GOREWEAR LARQ MitoQ K 19SPORTS solo stove BULK NUTRIENTS PURE SUPPLEMENTS SPICEOLOGY YETI 4 C L E S Murad. bensons for beds LA PERIA SOG STUDIES AND OBSERVATIONS Fortune Brands A home and security company#18B COMPOSABLE (HEADLESS) Customer snapshot by integration NEXT.B Gatsby NuxtJS WORDPRESS contentful CONTENTSTACK @algolia o bloomreach Ollie le petit planet FORCITE Black Diamond K2 SPICEOLOGY LONDON TED BAKER VP VIDEOPRO solo stove holly yashi Airomé MITOQ LA PERLA 19SPORTS unu Good Beautiful Mountain Equipment Company MKM YETI GOREWEAR CANDLE WARMERS Kōkatat bensons for beds LARQ springbok APPELLES. Murad. THE SCHOOL OF LIFE SOGE STUDIES AND OBSERVATIONS Fortune Brands A home and security company#19B Commerce-as-a-Service Enable commerce anywhere, powered by BigCommerce 4 BigCommerce enables partners to create and sell customized commerce solutions powered by our platform technology. Ability to go-to-market with partners to serve more merchants in more ways and more places Tailor ecommerce to the specific needs of a category or use case ↓↑ avasam clover Cross-sell ecommerce fully integrated with a technology, application or service Payu silk Localize BigCommerce anywhere in the world in terms of sales, marketing, service WINE DIRECT InfoTrax </> UNBOUND COMMERCE Jmango Extend commerce to mobile apps, devices, form factors, and virtual use cases Zarla Embed ecommerce trial experiences within an existing offering 19#20B Strong enterprise customers across multiple verticals Health & Beauty MOLTON BROWN LONDON Apparel Electronics Home & Garden Food & Beverage Sports & Outdoors Automotive B2B & Industrial Chap Stick BADGLEY MISCHKA. BULK NUTRIENTS XGREEN ROADSⓇ Nature's One PURE SUPPLEMENTS ONE KINGS LANE THE musicdirect KRA SPORTS. WINE GORE® FARMER BOY FLYER 'EUROSPORT TUNING WEAR M Mrs. birdsnest MEYER'S chairking CARILOHA BURROW DUXIANA BACKYARD STORE CLEAN DAY BEER CARTEL) Tienda Chivas SHARP Appliances FORCITE V ITS NATORI LA PERIA Lammes CANDIES a SINCE 1885 ROCK GOLF BOTTOM Nikon PRIORITY TIRE Leica ℗ pure barre Harvard Business Publishing Corporate Learning PETER CHRISTIAN vodafone JIMMY BRINGS YETI MOONBIKES A KYOCERA SGS Precision Tools MITOQ Ollie AN Brock's PERFORMANCE Black Diamond LARQ GRENSON ENGLAND 1866 dippine dots CHEM BRICKHOUSE SECURITY. solo stove mountain rose herbs Victoriahealth Mountain Equipment Company ABI AND JOSEPH Skullcandy AMERICAN LEATHER marucci VAN CAFE fart callins, colorado JOHNNIE WALKER BASKITS TECTRAN Driven to be BETTER™ FOLD B3 NORWALL POWER SYSTEMS Big Green Egg The Ultimate Cooking Experience ******** WHEELS www.bbwhoolsonline.com ONIT AQUA GROUP (NOM): BAKING FishUSA AMERICA'S TACKLE SHOP* COMPANY mazda#21BackOffice, PIM, B2B, Hosting CMS BACKOFFICE PEOPLEVOX Brightpearl SKUVAULT An incredible ecosystem of best of breed partner solutions LINNWORKS Acumatica skubana OMNISTOCK ΚΑΤΑΝΑ B2B PIM BIGCOMMERCE B2B EDITION behalf xentral ORACLE NETSUITE netlify CMS/HOSTING/HEADLESS logicbroker. TradeCentric Jmango Formerly PunchOut2Go o bloomreach CONTENTSTACK™ contentful Vue Storefront magnolia STYLA shogun Acquia prismic umbraco B storyblok DEITY FALCON uniform Vercel akeneo inRiver sales layer CREDIT KEY Sage FedEx. FRONT. COMMERCE SALSIFY comestri. Plytix pimberly Insights, Tax & Accounting TAX & ACCOUNTING Avalara AvaTax quickbooks VERTEX xero INSIGHTS Pay Helm Segment ll"Fueled Ⓡ Google Big Query Shipping SHIPPING & FULFILLMENT ShipStation® SHIPPER HQ ShipBob shippo 90+ PREFERRED & ELITE DHL Globale sendcloud Happy Returns by PayPal Digital River DROPSHIPPING huboo ~unarvar avasam spocket Odoba Payments & FinTech PAYMENTS PayPal affirm) stripe Omnichannel MARKETPLACES & AD PLATFORMS ROUTE Google Shopping facebook Instagram Tik Tok parcelLab Target+ ebay Microsoft amazon Braintree adyen worldpay Klarna. mollie PARTNERS nexi barclaycard authorize net cybersource Opayo Payu A Visa Solution checkout.com mercado pago WALLETS & ACCELERATED CHECKOUT PayPal amazon pay G Pay Pay BOLT B Walmart MULTICHANNEL LISTINGS / FEEDS Sales & Orders feedonomics codisto channelengine ADVERTISING CAMPAIGN MANAGEMENT POS O TEAMWORK COMMERCE clover OMS au libre mercado BigCommerce PARTNER 1,000+ APPS fluentcommerce deckcommerce ROI DYNAMIC HUNTER CREATIVE posnow □ Square Zettle by PayPal PIPE17 Marketing Automation EMAIL & MARKETING AUTOMATION dotdigital Constant Contact attentive mailchimp LOYALTY, REVIEWS & UGC AANNEX CLOUD LOYALTYLION nosto INTELLIGENT MERCHANDISING searchspring sendlane omnisend klaviyo Privy hawksearch By Bridgeline RATINGS & REVIEWS yotpo. Stamped LOYALTY & REWARDS smile.io bloomreach algolia Attragt dynamic yield segmentify FAST ✩ KLEVU SIMON Formerly instantach MOBILE yotpo. Trustpilot J Judge.me SHOPGATE CUSTOMER SUPPORT & CRM LiveChat zendeskgorgias HubSpot UNBOUND JMANGO COMMERCE Stamped REVIEWS & RATINGS 50+ INDUSTRY CATEGORIES 21#22Financials#23B Continued focus on high value enterprise accounts as mix continues to shift further towards larger B2C and B2B merchants 43% 57% Enterprise account ARR as a % of total ARR 41% 59% 37% 36% 63% 64% 33% 67% 30% Enterprise account ARR 70% 29% 28% 28% 71% 72% 72% Retail account ARR 29% 1Q21 2Q21 3Q21 4Q21 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 71% +54% +58% $123M $112M Enterprise account ARR ($M) +72% +78% $173M $160M +68% $189M *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition +35% +68% $216M $207M +21% +30% $229M $224M +14% $236M 1Q21 2Q21 3Q21 4Q21 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 23#24B Resilient subscription revenue growth through strategic shift to enterprise accounts, despite slower trends in consumer spending +22% YoY $112M $29M $83M +36% $152M $49M $104M 2019 y/y: Subscription Services 17% y/y: Partner and Services 38% 2020 25% 65% Subscription Services Note: Amounts may not add due to rounding. +44% $220M $65M $155M 2021 49% 33% Partner and Services +27% $279M $73M $206M 2022 33% 13% +41% $47M $15M +35% $49M $15M $32M $34M 1Q21 2Q21 +49% $59M $17M $42M +50% $65M $18M +42% $66M $18M $47M $48M *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition +22% +12% +39% $72M $72M $72M $68M $17M $19M $51M $53M 52% 22% 30% 34% 23% 12% +11% +9% $75M $19M $18M $54M $53M 3Q21 4Q21 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 36% 42% 59% 58% 50% 51% 26% 14% 12% 10% 12% 6% $19M $56M -1% 14%#25B Healthy gross margin profile leading path towards profitable growth +22% YoY $85M 2019 % of total revenue: 76% Non-GAAP gross profit ($M) +40% $119M 2020 78% +46% $174M 2021 79% +23% $213M 2022 76% 81% $38M 80% $39M 80% $47M Non-GAAP gross profit ($M) 77% 76% 77% 77% $56M $55M $56M 76% 75% $52M $49M $50M 77% $58M 1Q21 2Q21 3Q21 4Q21 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 Note: Non-GAAP gross profit and gross margin exclude the effect of stock-based compensation and related payroll tax expense. See appendix for reconciliation of Non-GAAP measures to GAAP. 25#26Driving leverage to deliver positive adjusted EBITDA Q4'23 Non-GAAP operating expense as % of revenue 17% 38% 55% 2019 Operating margin: (34%) 18% 30% 48% 2020 (18%) 19% 27% 43% 2021 (10%) 20% Sales & Marketing 27% 46% 2022 (17%) Operating (7%) Margin % 19% 26% 1Q21 Non-GAAP operating expense as % of revenue Research & Development (9%) 19% 43% 43% 27% (6%) 18% 25% (18%) (19%) 21% 20% 28% 43% 45% 28% General & Administrative 46% (20%) 21% 28% 48% (16%) 22% 26% (13%) 19% 26% (9%) 19% 24% (4%) 16% 23% 45% 44% 43% 42% 2Q21 3Q21 4Q21 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 Note: In Q1 2023, we reclassified certain costs that we had previously included in general and administrative expense into sales and marketing expense. To maintain consistency between comparable periods, the equivalent change has been applied to prior periods. This change in classification had no effect on the reported results of our operations or cash flow. Note: Non-GAAP operating expenses and operating margin exclude the effect of stock-based compensation and related payroll tax expense. See appendix for reconciliation of Non-GAAP measures to GAAP. Amounts may not add due to rounding. 26#274 Consistent merchant cohort growth, driven by increases in GMV and enterprise net revenue retention As merchants transact and grow in GMV, net revenue retention improves for SMB, mid-market, and enterprise base Strong LTV to CAC ratio of 3.8:1 for 2022 NRR for enterprise accounts was 111% in 2022 2016 2017 Annual Merchant Billings by Cohort 2018 2019 2020 2021 2022 Pre-2017 2017 cohort 2018 cohort ■2019 cohort 2020 cohort 2021 cohort ■2022 cohort Note: Annual Merchant Billings by Cohort includes both subscription plan revenue and partner and services revenue for the enterprise account cohort that joined the platform in the indicated period. 27#28Key Metrics 1 Annual revenue run-rate 2 Subscription annual revenue run-rate 3 Annual revenue run-rate for enterprise accounts 4 Enterprise accounts as a percent of annual revenue run-rate 5 Average revenue per account for enterprise accounts 6 Number of enterprise accounts 28#29BARR growth expected to improve behind increased focus and investments in high value, high retention enterprise accounts... (as of 6/30/23) 1 +22% YoY $108M Q1 +26% +25% $121M $115M Q2 2019 +26% $129M Q3 +27% $152M $137M Q4 Q1 +32% $167M Q2 +38% $181M Q3 2020 Total ARR ($M) +41% $196M Q4 +38% +43% $209M Q1 Q2 +52% $269M $254M Q3 2021 +48% $280M +41% +43% $296M Q4 Q1 +20% $305M Q2 Q3 2022 +16% +13% $312M $317M +12% $331M Q4 Q1 Q2 2023 *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition Note: Annual revenue run-rate ("ARR") is calculated as the sum of: (1) contractual monthly recurring revenue at the end of the period, which includes platform subscription fees, invoiced growth adjustments, feed management subscription fees, recurring professional services revenue, and other recurring revenue, multiplied by twelve to prospectively annualize recurring revenue, and (2) the sum of the trailing twelve-month non-recurring and variable revenue, which includes one-time partner integrations, one-time fees, payments revenue share, and any other revenue that is non-recurring and variable. 29#30(as of 6/30/23) 2 $84M ...with Subscription ARR growth pacing ahead of non-subscription ARR... Q1 $89M $94M +24% $99M $104M 2019 +23% YoY Q2 Q3 Q4 Q1 +28% $114M +31% $123M Q2 Q3 2020 Subscription ARR ($M) +34% $133M Q4 +37% $143M Q1 +34% $153M Q2 +57% $193M 2021 Q3 +54% $204M Q4 +48% +49% $226M $212M Q1 Q2 +15% +17% +21% $244M $238M $233M Q3 2022 +13% $256M Q4 Q1 Q2 *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition Note: "Subscription annual revenue run-rate" is calculated by subtracting the trailing twelve months of partner and services revenue from Total annual revenue run-rate 2023 30#31(as of 6/30/23) 3 ...and enterprise accounts outpacing non-enterprise accounts and partner and services revenue +44% YoY +46% $51M $55M Q1 +44% $61M Q2 Q3 2019 +44% +40% $67M $71M T Q4 Q1 +44% $80M Q2 Q3 Enterprise ARR ($M) +48% $101M $90M 2020 +54% +58% $123M +51% $112M Q4 Q1 Q2 *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition Note: Enterprise accounts represent any account with at least one BigCommerce enterprise plan +78% $160M Q3 Q4 2021 +68% +68% $207M +72% $189M $173M Q1 +35% $216M +30% $224M Q2 Q3* Q4 2022 +21% $229M +14% $236M Q1 Q2 2023 31#32B 71% of ARR from enterprise accounts today, driven by durable growth in mid market and enterprise segments (as of 6/30/23) 47% Q1 48% 50% Q2 Q3 2019 52% % of ARR attributable to enterprise accounts Q4 Q1 Q2 54% 53% 52% 56% 2020 57% 59% Q3 Q4 Q1 Q2 Note: Enterprise accounts represent any account with at least one BigCommerce enterprise plan 63% Q3 2021 64% Q4 67% Q1 70% 71% 72% 72% 2022 71% Q2 Q3 Q4 Q1 Q2 2023 32#33Mid market strength and up market progress into enterprise segment driving B steady growth in ARPA over time (as of 6/30/23) 5 +25% $21.9k +27% YoY $21.0k Q1 +24% $23.2k +22% $24.4k 2019 Q2 Q3 Q4 Q1 ARPA attributable to enterprise accounts ($k) +17% +26% +17% $33.3k +23% $31.6k $31.4k +22% $29.9k +23% $28.4k +19% $26.9k $25.1k 11 Q1 Q2 Q3 2020 Q4 Q2 +15% $34.3k Q3 Q4 2021 +22% $38.1k +12% $35.2k Q1 +17% +13% $38.9k $38.7k Q2 +11% +5% $39.3k $39.9k Q3 Q4 Q1 Q2 2022 Note: Average revenue per account ("ARPA") for enterprise accounts is calculated at the end of a period by including customer-billed revenue and an allocation of partner and services revenue, where applicable. 2023 33#34B (as of 6/30/23) 6 Mid market and enterprise focus yielding account growth and opportunities with larger, more complex customers +13% YoY 2.4k Q1 +17% 2.5k Q2 +17% +17% 2.7k 2.6k 1 Q4 2019 +17% 2.8k Q3 Q1 +17% 3.0k Number of enterprise accounts ($k) +21% 3.2k Q2 Q3 2020 +23% 3.4k Q4 +32% +26% 3.9k 3.6k Q1 +51% +38% 5.4k +50% 5.4k +52% 5.0k 4.8k +16% 5.6k Q2 Q3 Q4 Q1 Q2 Q3* 2021 2022 *Note: Q3 2022 marks the 1 year anniversary of the Feedonomics acquisition Note: Enterprise accounts represent any account with at least one BigCommerce enterprise plan. Year-over-year growth rates may not compute due to rounding. +15% 5.8k Q4 +9% +9% 5.8k 5.9k Q1 Q2 2023 34#35Investment highlights Large and growing addressable market Strong, long-term secular tailwinds tied to digital commerce with TAM expanding beyond ecommerce platform spending in the US and abroad Open SaaS Disruptive platform and partner approach that prioritizes enterprise functionality, best of breed technologies and freedom of choice for all merchants Consistent revenue growth Revenue mix shift to mid-market and enterprise customers driving durable, consistent revenue growth and strong unit economics Strong gross margins High margin revenue share from established partnership agreements has driven consistently high gross margins Increasing operating leverage Continuing to invest in long-term growth opportunities while managing spend to hit adjusted EBITDA break-even Q4'23 35#36Appendix#37GAAP income statement Figures in thousands Revenue Cost of Revenue (¹) Gross Profit Operating Expenses Sales & Marketing (1) Research & Development (¹) General & Administrative(1) Acquisition Related Expenses Restructuring Charges Amortization of Intangible Assets Total Operating Expenses Loss from Operations Interest Income Interest Expense Other (Expense) Income Loss Before Provision for Income Taxes Provision for Income Taxes Net Loss (1) Includes stock-based compensation. Three Months Ended June 30 (Unaudited) 2023 $75,443 18,756 56,687 35,593 21,403 14,428 4,125 2,033 77,582 (20,895) 2,825 (722) (63) (18,855) 210 ($19,065) 2022 $68,203 16,860 51,343 36,033 22,394 17,526 12,521 2,009 90,483 (39,140) 577 (705) (297) (39,565) 40 ($39,605) Six Months Ended June 30 (Unaudited) 2023 $147,200 36,202 110,998 69,645 42,248 30,922 8,250 420 4,066 155,551 (44,553) 5,251 (1,444) (32) (40,778) 407 ($41,185) 2022 $134,253 33,963 100,290 69,672 43,339 33,372 25,181 4,046 175,610 (75,320) 699 (1,414) (452) (76,487) 155 ($76,642) 37#38Non-GAAP reconciliation Figures in thousands Gross Profit GAAP Gross Profit Stock-based Compensation (¹) Non-GAAP Gross Profit Non-GAAP Gross Margin Sales & Marketing GAAP S&M Expense Stock-based Compensation(¹) Non-GAAP S&M Expense Non-GAAP S&M as % of Revenue Research & Development GAAP R&D Expense Stock-based Compensation (¹) Non-GAAP R&D Expense Non-GAAP R&D as a % of Revenue General & Administrative GAAP G&A Expense Stock-based Compensation (¹) Non-GAAP G&A Expense Non-GAAP G&A as % of Revenue Operating Loss GAAP Operating Loss Stock-based Compensation(¹) Acquisition Related Expenses Restructuring Charges Amortization of Intangible Assets Non-GAAP Operating Loss Non-GAAP Operating Margin Q1'21 Q2'21 Q3'21 $37,410 $38,828 $46,882 415 545 310 $37,825 $39,373 $47,192 81% 80% 80% $21,960 $23,676 1,913 $20,047 43% $13,535 1,267 $12,268 26% $10,457 1,824 $8,633 19% $27,438 2,461 2,192 $21,215 $25,246 43% 43% ($3,123) (7%) $14,725 $16,532 1,526 1,624 $13,199 $14,908 27% 25% $11,591 2,405 $9,186 19% $13,033 2,167 $ 10,866 18% ($4,227) (9%) Q4'21 FY 2021 $48,256 $171,376 852 2,122 $49,108 $173,498 76% 79% 1,402 ($3,828) (6%) $31,771 $104,845 2,828 9,394 $28,943 $95,451 45% 43% Q2'22 Q1'22 $48,947 $51,343 868 987 $49,815 $52,330 75% 77% $16,263 $51,344 2,454 8,850 $13,809 $42,495 21% 19% $33,639 $36,033 2,975 3,567 $30,664 $32,466 46% 48% ($8,542) ($12,271) ($21,315) ($33,815) ($75,943) ($36,179) 5,419 $6,937 1,107 $6,293 9,792 7,887 26,535 12,400 23,299 9,108 12,660 Q3'22 $54,866 1,091 $55,957 77% $35,973 3,254 $32,719 45% $15,846 $17,526 $18,932 2,702 3,338 3,296 $13,144 $14,188 $15,636 20% 21% 22% ($39,140) ($30,560) 10,934 10,785 6,260 12,521 Q4'22 FY 2022 Q1'23 $53,939 $209,095 $54,311 1,280 4,226 1,189 $55,219 $213,321 $55,500 76% 76% 77% $19,755 $64,547 $20,944 $22,394 $22,245 $22,669 $88,253 $20,845 $21,403 1,753 6,170 2,563 3,042 3,144 3,639 12,388 3,503 3,943 $18,003 $58,377 $18,381 $19,352 $19,101 $19,030 $75,865 $17,342 $17,460 28% 27% 28% 28% 26% 26% 27% 24% 23% 1,882 3,284 2,037 2,009 2,016 ($11,647) ($22,825) ($12,374) ($13,676) ($11,499) (18%) (10%) (19%) (20%) (16%) $35,697 $141,342 3,757 13,553 $31,940 $127,789 44% 46% $34,052 2,867 $31,185 43% Q2'23 $56,687 1,290 $57,977 77% $35,593 3,566 $32,027 43% $17,137 $69,441 $16,494 $14,428 3,483 12,819 3,079 2,573 $13,654 $56,622 $13,415 $11,855 19% 20% 19% 16% (1) Includes payroll tax associated with stock-based compensation expense. Note: In Q1 2023, we reclassified certain costs that we had previously included in general and administrative expense into sales and marketing expense. To maintain consistency between comparable periods, the equivalent change has been applied to prior periods. This change in classification had no effect on the reported results of our operations or cash flow. ($34,687) ($140,567) ($23,658) ($20,895) 12,159 42,986 10,638 11,372 4,125 420 4,125 3,775 35,216 7,332 7,332 2,016 8,078 2,033 ($9,405) ($46,955) ($6,442) (17%) (13%) (9%) 2,033 ($3,365) (4.5%) 38#39Adjusted EBITDA reconciliation Figures in thousands Net Loss Stock-based Compensation Expense Payroll Tax Associated with Stock-based Compensation Expense Third-party Acquisition Related Costs Depreciation Amortization of Intangible Assets Interest Income Interest Expense Provision for Income Taxes Restructuring Charges Other Income/Expense Adjusted EBITDA Three Months Ended June 30 2023 ($19,065) 11,290 82 4,125 906 2,033 (2,825) 722 210 63 ($2,459) 2022 ($39,605) 10,578 356 12,521 812 2,009 (577) 705 40 297 ($12,864) Six Months Ended June 30 2023 ($41,185) 21,777 233 8,250 1,778 4,066 (5,251) 1,444 407 420 32 ($8,029) 2022 ($76,642) 19,540 502 25,181 1,601 4,046 (699) 1,414 155 452 ($24,450) 39#40B Non-GAAP net loss reconciliation Figures in thousands Net Loss Stock-based Compensation Expense Payroll Tax Associated with Stock-based Compensation Expense Third-party Acquisition Related Costs Amortization of Intangible Assets Restructuring Charges Non-GAAP Net Loss Three Months Ended June 30 2023 ($19,065) 11,290 82 4,125 2,033 ($1,535) 2022 ($39,605) 10,578 356 12,521 2,009 ($14,141) Six Months Ended June 30 2023 ($41,185) 21,777 233 8,250 4,066 420 ($6,439) 2022 ($76,642) 19,540 502 25,181 4,046 ($27,373) 40