RECONCILIATION · ONE OF FOUR
The order total changed after checkout, and now the payment does not match
A customer starts a checkout at €120, amends it to €150, and pays €150. Your order system has both numbers. Your payment provider has one. Depending on which export you pulled and when, the two disagree by €30 — and both are correct.
What is actually happening
A changed basket is one possible explanation. Confirm the revision and authorization before concluding that the payment is correct. The two records describe two different versions of the same purchase, and nothing in either export says which version it is.
A basket is not a fixed thing. It is amended, a discount is applied late, shipping is recalculated, an item goes out of stock between the checkout starting and the payment completing. Each of those produces a new total. Your order system, doing its job, keeps the history. Your provider only ever sees the amount it was asked to charge.
How to tell it is this one
You will find two order totals carrying the same identifier, or a total that changed between two exports taken on different days.
The distinguishing signal is that the captured amount matches one of the totals exactly — not approximately, exactly. A mismatch caused by fees or currency conversion lands on a number that matches nothing.
If you export the order again today and the total has moved, you have your answer without looking at the payment side at all.
What to do
Nothing to the money. Do not adjust, do not refund a difference, do not issue a top-up charge. First confirm that the capture matches the authorized revision.
Fix the export instead. Each version of a basket needs to carry its own identifier, so a comparison can ask which version was paid for rather than what is the total. Once the records can express that, the disagreement stops being a disagreement and becomes an ordinary fact about an amended order.
Until then this will recur every single time a customer changes their mind, and somebody will spend a morning on it every time.
This is one of four
A mismatch between an order system and a payment provider takes four shapes. Each needs to be checked against the source records and may need a different response — which is why the week gets spent arguing about which system is wrong.
IF YOU WANT THIS DONE FOR YOU
I build software that does this,
and I take engagements on it.
You send anonymised order, capture and refund records. I return the findings with evidence your engineers can recompute offline, without the tool that produced them.