Sunlight

Sunlight is an API to change the card-on-file with apps and subscription services. Fintechs use Sunlight to automatically make their cards top-of-wallet as soon as they're issued.

Merchants, service providers and subscriptions-based businesses everywhere now offer their customers the ability to save a debit/credit card on file, so they can pay their bills on time, buy in one click, or earn rewards. In 2021, 79% of consumers worldwide reported already having at least one payment card saved with a service or being open to doing so.

In recent years, card-issuing as-a-service has become mainstream: any company can now start their own card business in a matter of weeks. Last year, the number of new payment cards issued was at an all-time high. For users, however, switching banks or opening a new card now comes with an additional hurdle: they need to update their payment info across the internet. On the other side of that equation, card issuers have no visibility or control over the card-on-file updating process, and as a result struggle to get their new users to switch their spend from their old card to the new one, leading to low conversion rates and missed revenue opportunities.

Until Sunlight.

With our universal get-your-card-on-file API, FIs can now offer their users, at any point in their journey, a quick and easy way to update their debit/credit card info everywhere they shop or pay online, without ever leaving their Apps.

The Sunlight API works on every platform that has a card-on-file option (think Uber, Amazon, Netflix, DoorDash, Starbucks and so many more…), is as seamless as a Plaid connection, and always gets the card number and CVV code right on the first try!

High-Level Overview

Sunlight offers a universal Card-On-File API designed to automate the management and updating of saved payment card information across multiple apps and subscription services. This platform primarily serves fintech companies, banks, merchants, and subscription-based businesses by reducing payment failures and improving transaction success rates through seamless card updates. By enabling financial institutions to instantly make their newly issued cards the "top-of-wallet" across popular platforms like Uber, Amazon, Netflix, and others, Sunlight enhances customer convenience and boosts card usage and interchange revenue[1][2][3][5].

For an investment firm, Sunlight represents a fintech innovation that streamlines digital payments, a sector experiencing rapid growth due to increasing consumer adoption of digital wallets and subscription services. The company’s impact on the startup ecosystem lies in its facilitation of smoother payment flows and increased card transaction volumes, which can accelerate fintech product adoption and customer lifetime value[1][2][5].

For a portfolio company, Sunlight builds a developer-friendly API product that serves fintechs, banks, and merchants. It solves the problem of cumbersome manual card updates by automating card-on-file refreshes, thereby reducing payment declines and improving customer retention. The company has demonstrated strong growth momentum, securing partnerships with major fintechs and financial institutions, and expanding its integration footprint across a wide range of consumer and business platforms[1][2][3][5].

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Origin Story

Sunlight was founded by a team with deep expertise in fintech, data integrations, and high-performance system architecture. The idea emerged from the recognition that while card issuance has surged, users face friction updating their payment information across multiple services, and financial institutions struggle to convert new card issuance into actual spend due to lack of control over card-on-file updates[2][5].

The company participated in Y Combinator’s Summer 2022 batch, which helped accelerate its product development and market fit. Early traction came from fintechs and banks adopting Sunlight’s API to improve card adoption metrics and reduce payment failures. The founders’ complementary skills and clear focus on building a best-in-market product have been pivotal in navigating challenging macroeconomic conditions and scaling the business[2][5].

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Core Differentiators

• Universal API: Works across all platforms that support card-on-file payments, including major consumer and business merchants.
• Seamless Integration: Designed for developers to easily embed into existing payment workflows, similar in ease to Plaid.
• Instant Top-of-Wallet Placement: Enables financial institutions to make newly issued cards the preferred payment method immediately.
• Improved Payment Success: Automates card updates to reduce declines and increase transaction success rates.
• Boosts Share of Wallet: Helps businesses migrate recurring spend to their cards quickly, increasing customer lifetime value and interchange revenue.
• Security and Privacy: Complies with the highest security standards to protect sensitive payment data.
• Strong Fintech Partnerships: Trusted by leading fintechs and financial institutions, with backing from Y Combinator, SV Angel, Liquid 2 Ventures, GFC, and Fiat Ventures[1][2][3][5].

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Role in the Broader Tech Landscape

Sunlight rides the digital payments and embedded fintech trend, where consumers increasingly prefer seamless, automated payment experiences. The timing is critical as card issuance has reached record highs, but the friction in updating card-on-file details limits card usage and issuer revenue. Market forces such as the growth of subscription services, e-commerce, and digital wallets create strong demand for solutions that reduce payment failures and improve user experience.

By enabling instant card updates across multiple platforms, Sunlight influences the broader ecosystem by increasing card transaction volumes, enhancing issuer control over spend migration, and supporting fintech innovation in payment infrastructure. This positions Sunlight as a key enabler in the modernization of finance operations and digital commerce[1][2][3][5].

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Quick Take & Future Outlook

Sunlight is well-positioned to capitalize on the ongoing expansion of digital payments and the increasing complexity of card management in a multi-platform world. Future growth will likely be driven by deeper integrations with more merchant platforms, expansion into B2B payments, and enhanced features around invoice payments and receipt capture.

Trends such as embedded finance, real-time payment updates, and increased regulatory focus on payment security will shape Sunlight’s journey. Its influence may evolve from a niche API provider to a foundational infrastructure player in the fintech ecosystem, helping issuers and merchants maximize card usage and customer retention.

As digital commerce continues to grow, Sunlight’s universal card-on-file API could become the standard for card management, tying back to its mission of simplifying and automating payment flows for businesses and consumers alike[1][2][3][5].