Topic guide · 23 pages

How do payments work in an app or SaaS product?

Updated 5 November 2026 · every page on this topic, checked against our own builds

Quick answer

A payment feature is four parts: the gateway that takes the money, the ledger that records it, the payouts that move it to sellers or trainers, and the rules your market applies. In India that means RBI rules on recurring payments and GST invoices; elsewhere, card and tax rules. Start with the gateway guides for Razorpay subscriptions and Stripe, then read the RBI rules.

We have built card payments and payouts in production for Trainr, Razorpay checkout and subscriptions for our own products and Proton, and a payment-and-ledger audit on Storafleet. These pages hold what we learned, including the edge cases that only show up with real money.

Start here

01Integration guidesRazorpay Subscriptions
02Integration guidesStripe payments, refunds and payouts
03GuidesRBI Payment Aggregator Rules

Every page on payments in apps

Gateways and payouts

Integration guidesRazorpay SubscriptionsRecurring billing on Razorpay, with mandates and retries
Integration guidesOne Razorpay account for several appsRunning several products on one Razorpay account
Integration guidesStripe payments, refunds and payoutsCard payments and connected-account payouts on Stripe
Integration guidesRevenueCat in-app subscriptionsIn-app subscriptions across both app stores
ArticlesRazorpay vs Stripe for an Indian SaaS: How to ChooseWhich gateway suits an Indian SaaS selling worldwide

Rules and tax

GuidesRBI Payment Aggregator RulesWhat RBI rules mean for recurring and marketplace payments
GuidesGST E-invoicing for SoftwareGST invoices and e-invoicing for software businesses
ArticlesUAE VAT for Apps and Marketplaces: Decide Before You BuildVAT on app subscriptions and marketplace commissions in the UAE

Terms to know

GlossaryPayment gatewayWhat a gateway does and what it leaves to you
GlossaryLedgerThe record every balance and refund is checked against
GlossaryPayoutMoving money from the platform to sellers
GlossaryReconciliationMatching gateway reports to your own ledger
GlossaryRefundRefunds that keep the ledger and invoices right
GlossarySubscription billingPlans, renewals, retries and proration
GlossaryEscrowHolding money until a service is delivered
GlossaryWalletIn-app balances and what the rules allow
GlossaryMinor unitsStoring money as whole paise or cents
GlossaryIdempotencyMaking sure a retried payment is never charged twice

Where we build it

ServicesSaaS PlatformsSubscription billing, tenants and invoices for SaaS products
ServicesShopify & WooCommerce DevelopmentCheckout and payments for Shopify and WooCommerce stores
SolutionsMarketplace appsCommissions, payouts and refunds for marketplaces
Case studiesTrainrLive card payments and trainer payouts
Case studiesStorafleetSubscription billing checked by a payment-and-ledger audit

Questions people ask about payments in apps

Do I need my own ledger if the payment gateway already records every payment?

Yes, as soon as money moves more than once: refunds, payouts, wallet balances or credits. The gateway knows what it charged; only your ledger knows what each user and seller is owed. Reconcile the two daily.

Can an Indian startup take payments from customers in other countries?

Yes. Both Razorpay and Stripe support international cards for Indian businesses, with different onboarding and fees. Our Razorpay vs Stripe comparison covers which suits a SaaS selling worldwide.

What changes when payments go to sellers instead of to us?

You become a marketplace: you need seller onboarding and KYC, payouts on a schedule, refunds that reverse the commission, and rules on holding money. The RBI guide explains the Indian side.

Do in-app purchases have to go through Apple and Google?

For digital goods used inside the app, usually yes. Physical goods and real-world services, such as a delivery or a training session, can use your own gateway. See in-app purchase.

How do you test payments without moving real money?

In the gateway's test mode with test cards, then a small live payment and refund before launch, with the ledger checked at each step.

What goes wrong most often in payment code?

Webhooks handled twice, refunds made in the gateway dashboard that never reach the ledger, and money stored as decimals that round. The Storafleet audit found the second and its fix is on the case study.