Connect an InPost Pay sandbox account

Get InPost Pay test credentials and connect them to your store so shoppers can pay in the InPost Mobile app.

InPost Pay lets shoppers finish the purchase in the InPost Mobile app – one tap with card, BLIK, Apple Pay or Google Pay, usually with delivery to a Paczkomat. InPost takes the payment and pays you directly.

A sandbox is a pretend version of InPost Pay. You can run test payments and no real money moves.

Note: InPost Pay is not the same as the InPost shipping add-on. InPost Pay takes the money; the shipping add-on books parcels and prints labels – see Ship with Polish carriers. You can use both.

Before you start

  • Ask us to turn it on. InPost Pay is in early access, so the add-on doesn't show on your Add-ons page yet. Reach us through Get help and support and we'll enable it for your store.
  • Sell in PLN. InPost Pay works only for carts in Polish złoty. Shoppers with a cart in another currency don't see the button.

1. Get your credentials from InPost

There's no self-service sign-up. InPost sets up the account for you.

  1. Write to integracjapay@inpost.pl and ask for an InPost Pay sandbox account.
  2. Ask them for the webhook secret too – InPost sends it separately, only on request.
  3. Keep the onboarding email. It contains your client ID, client secret, merchant client ID and POS ID (it starts with V).

2. Paste the credentials into your store

  1. In your store admin open Add-ons → InPost Pay.
  2. Find the amber Sandbox box.
  3. Fill in Client ID, Client secret, Merchant client ID (widget), POS ID and Webhook secret.
  4. Leave Merchant external ID (signatures) empty – your store fetches it from InPost when you save.
  5. Tick Active in sandbox.
  6. Click Save InPost Pay settings.

3. Give InPost your store's addresses

  1. Under URLs to give InPost copy the Merchant Backend API base URL and the Transactional webhooks (v2) address.
  2. Register both at merchant.inpost.pl. InPost sends three kinds of notifications (payments, refunds, settlements) – use the same webhook address for all three.
  3. Ask integracjapay@inpost.pl to allow-list your storefront domain – the one shoppers see the button on.

Done. While your store is in test mode, InPost Pay uses the sandbox.

Good to know

  • The InPost Pay button stays hidden from shoppers until InPost certifies your store. Once they do, we switch it on for you.
  • Sandbox and production credentials are different. Sandbox credentials go only in the amber Sandbox box, production credentials only in the green Production box.
  • Issue refunds from the order as usual. They show as pending until InPost confirms them – see Issue refunds and handle returns.
  • Before you start selling for real, ask InPost for production credentials, add them to the Production box, tick Active in production and switch your store to live mode.