Deposit and balance-payment flow for a camp registration store

The challenge

A business taking registrations for camps sold places through an online store and let families pay a deposit up front, using our partial-payment module. That solved the first step, but not what came after it. Staff had no simple way to see which registrations still had money owing, families had no straightforward way to pay the rest online, and when an administrator edited an order, the outstanding amount could drift out of step with what had actually been charged.

The store ran OpenCart 2.1.0.1, so the module itself needed updating for that release before any of this could be built.

What we did

• Module update. We updated our partial-payment module for OpenCart 2.1.0.1 and delivered the new package for testing on the client's test store.
• Outstanding balances in admin. We added a filter to the admin order list so staff can pull up every order with a pending amount, giving a clear view of outstanding balances.
• Online balance payments. Customers now see a "Pay" option against their orders in order history. The balance flow works with PayPal Pro and with cheque or money order, and we corrected a case where the full order total, rather than the remaining balance, was being charged.
• Correct amounts with the gateway. We fixed a mismatch between the pending amount shown in the store and the amount charged through PayPal, and tidied when the Pay button is shown.
• Order edits. When an administrator changes an order, the outstanding balance is now recalculated so the customer is always asked for the right amount.

Each change was delivered in a short, separately agreed round and tested on the client's test store.

Tech stack

PHP, MySQL, OpenCart 2.1, vQmod, PayPal Pro