How customers pay

The Stack sheet handles everything between “Pay with Stack” and “Paid”. You don’t build any of these screens.

1. Sign in with an email code

The customer enters their email and types the 6-digit code Stack sends. If you passed their email, the code goes out as the sheet opens.

• New to Stack: the code verifies their email, and their Stack account is created when this first payment succeeds. There’s no sign-up form.
• Used Stack in another app: it’s the same account, with the same balance and saved cards.
• Signed in to Stack in your app before: no code at all, straight to paying.

2. Choose how to pay

[Stack] Balance                 ₦12,400
Card ›      Visa •••• 4081 · Add a new card
Bank ›      GTBank · Connect a bank · Bank transfer

• Balance is always listed. It’s greyed out when it doesn’t cover the payment. Refunds land here, so returning customers often have one.
• Card lists saved cards, then Add a new card. Card details go straight to Stack and our payment processor, and your app never sees them. OTPs, card PINs and 3-D Secure happen in the sheet.
• Bank lists saved banks (direct debit), then Connect a bank (approve a debit once at the bank, then pay from it any time) and Bank transfer (a one-time account number for exactly this amount, valid for up to 30 minutes).

A card the customer saves is available at every Stack merchant, not just yours.

3. Confirm

	First payment	Returning, on a phone	Returning, on the web
Confirms with	The sign-in code	Face ID or fingerprint	Stack PIN
Falls back to	—	Stack PIN, then an email code	An email code

After a first payment, the sheet offers to set a 4-digit Stack PIN for next time. The customer can skip it.

4. Done

The sheet shows a tick and closes. presentPaymentSheet resolves with { status: 'succeeded' }, and your server receives the webhook.

Limits

Payments from a customer’s Stack balance are limited to ₦50,000 per payment and ₦200,000 a day until identity checks arrive. Card, bank and transfer payments aren’t limited by Stack. Over a limit, the sheet explains and the customer can choose another way to pay.