LiqPay — Card Payments for OpenCart 2.3, 3.x and 4.x

LiqPay for OpenCart is a payment module that accepts card payments (Visa/Mastercard, Apple Pay and Google Pay) through the secure LiqPay payment page. Once the customer pays, LiqPay sends a signed serviceUrl webhook, the module verifies the HMAC-MD5 signature and moves the order to the correct status itself. There’s no manual “paid or not” reconciliation — the status only changes once the money has actually gone through.

The base version is free. Download: liqpay.ocmod.zip (OpenCart 4.x) or liqpay-oc3.ocmod.zip (OpenCart 3.x). Free covers card payment acceptance and webhook-based order auto-confirmation; Pro adds a payment log with status reconciliation, two-stage payment (AUTH + SETTLE), and full and partial refunds straight from the admin panel.

What the admin gets

How it works — step by step

1. At checkout the customer chooses “Card payment (LiqPay)” and confirms the order.
2. The module builds a signed request and redirects the customer to the secure LiqPay payment page — card, Apple Pay or Google Pay. Card details are entered on LiqPay’s side and never reach your store.
3. After payment, LiqPay sends a serviceUrl webhook to the extension/liqpay/payment/liqpay.callback route. The module verifies the HMAC-MD5 signature against the raw request body and sets the order to the chosen “paid” status.
4. When the customer returns to the store, the status is additionally reconciled via the Status API — the order is only completed if the transaction genuinely succeeded.
5. With Pro: under the two-stage scheme, funds are only held (AUTH), and captured (SETTLE) automatically once you move the order to the “paid” status. Refunds — full or partial — are issued from the payment log.

Pricing

1,490 UAH — one-off purchase. The licence is perpetual: you pay once, and updates and technical support are included in the price. One key covers one domain and its subdomains.

Moving your store to another domain? Deactivate the licence on the old one and activate it on the new one yourself in your account.

The licence is perpetual — nothing expires or switches off. One key covers one domain; if you move your store, deactivate the licence on the old domain and activate it on the new one yourself.

One key covers one domain. If you move your store, deactivate the licence on the old domain and activate it on the new one yourself, without contacting support.

Trial first, payment after. A fresh install is the free version: Pro doesn’t switch itself on, and nothing shuts off after a week. When you want to try Pro, click “Try Pro” in the module settings, enter your email and get a 7-day key (also sent by email). That means you can check the transaction log, AUTH/SETTLE and refunds on your own store before buying — which is exactly why refunds after purchase aren’t offered.

Installation

1. Admin panel → Extensions → Installer → upload liqpay.ocmod.zip and click “Install”.
2. Admin panel → Extensions → Payment → find LiqPay and click “+” (this creates the module’s table, event and permissions).
3. Click “Edit”: enable the module, enter the keys from your LiqPay account. For testing, leave “Test mode” on and enter a pair of keys with the sandbox_ prefix.
4. There’s no need to register a webhook URL in your LiqPay account — the module passes it with every payment.

Technical requirements

• OpenCart 3.0.2 – 3.0.5.0 (the liqpay-oc3.ocmod.zip build) or 4.0.2 – 4.1.x (the liqpay.ocmod.zip build)
• PHP 7.4+
• LiqPay public and private key — from your LiqPay account; testing requires a separate pair of sandbox_ keys

Under the hood

• The signature is verified against the raw request body — OpenCart HTML-escapes POST data, so the webhook reads `php://input` directly; otherwise the signature wouldn’t match.
• Double payment verification: a signed webhook plus a Status API reconciliation when the customer returns.
• Idempotency — a repeated webhook doesn’t change the status a second time and doesn’t downgrade an already-confirmed order.
• The private key is encrypted with a key derived from the store’s path and database name — settings copied to another site won’t decrypt.

LiqPay is a trademark of JSC CB “PrivatBank”. This module is an independent integration and is not affiliated with LiqPay or PrivatBank.

Version history

1.0.4 — 2 August 2026

Fixed an underpayment issue: a callback for an amount less than the order total is no longer stored as a successful payment — the order stays unpaid with an underpayment note, and the next callback for the full amount correctly moves it to “Paid”. The licence now survives catcode.com.ua being unreachable: a network error is no longer treated as an “invalid key” response, so Pro doesn’t switch off during an outage (the 14-day grace period finally works). Partial refunds in the log are now totalled cumulatively — the remaining balance is correct after several refunds. The trial only starts on your own click; a fresh install is a clean free version.

1.0.1 — 23 July 2026

Fixed a checkout conflict on OpenCart 4.0.2.x: the geo-zone check no longer loads a catalog model missing in that version and no longer blocks the payment method selection.

1.0.0 — July 2026

First public release.