Pay Later: Afterpay, Clearpay and Zip for OpenCart 2.3, 3.x and 4.x — buy now, pay later

Pay Later: Afterpay, Clearpay and Zip is a payment module for OpenCart 4.x, 3.x and 2.3 with instalment payments through Afterpay, Clearpay and Zip. The buyer confirms the payment plan on the provider’s page, and the shop gets the full amount. Afterpay works in Australia, New Zealand, Canada and the US; in the UK the same service is called Clearpay; Zip works in Australia only, having left the UK and New Zealand.

The module adds two payment methods. An order becomes paid only when the module has captured the payment through the provider’s API and checked the attempt reference, the amount, the currency and that the order total has not changed.

What the buyer sees

At the payment step the buyer sees “Pay later with Afterpay” (or Clearpay for a UK account) or Zip, with a note that the payment plan is confirmed on the provider’s page. After confirming the order they go to Afterpay or Zip and come back to the shop.

If the buyer cancels, they see “Payment cancelled” and that no money was taken. If the provider does not approve the payment, the buyer sees that no money was taken and a button back to checkout to pick another method.

What the admin gets

In the Afterpay settings you pick the account country and the environment and enter the Merchant ID and Secret Key, and the module reads the amount limits from the account. The Zip settings take the private API key. A connection check shows whether the provider accepted the keys.

The order history gets a line about the payment with its ID. In Pro the order page has full and partial refunds and a re-check that picks up refunds made in the provider’s portal. The payment journal lists every Afterpay and Zip attempt, and the watchdog captures approved payments when the buyer never came back to the shop.

How it works, step by step

1. Enter your Afterpay or Zip keys and check the connection.
2. The buyer picks Afterpay, Clearpay or Zip at checkout.
3. The module creates a checkout at the provider and sends the buyer to its page.
4. The buyer confirms the payment plan and comes back.
5. The module captures the payment through the API and checks the amount, currency and reference.
6. Only then the order gets its paid status.

Under the hood

• Afterpay: Online API v2, a checkout per attempt, idempotent capture by token.
• Zip: Merchant API, a charge with each attempt’s own idempotency key and a read-back of the result.
• A payment can never confirm another order: the attempt reference and amount are checked.
• One shared code base for OpenCart 4.x, 3.x and 2.3, PHP 7.0 syntax.
• Keys are never written to the log.

How to install

1. Extensions → Installer: upload the archive for your version and keep the file name.
2. OpenCart 2.3: the Installer copies files only with FTP enabled. Without FTP copy the contents of upload/ to the shop root by hand.
3. OpenCart 2.3 and 3.x: Extensions → Modifications → Refresh.
4. Extensions → Payments → Pay Later: Afterpay, Clearpay and Zip → install button → Edit.
5. Extensions → Payments → Afterpay / Clearpay (CatCode): pick the account country and the sandbox environment, enter the keys.
6. For Zip, Extensions → Payments → Zip (CatCode), the private API key.
7. Check the connection, make a test payment and switch to the live environment.
8. For Pro: paste the key or start the 7-day trial.