Could several payments relate to one order?¶

Yes. One order can create multiple attempts, funding components, deposits, dispatch charges, adjustments and returns. Visible transaction count is not purchase count.

Status determines which values moved¶

Customers can split funding across cards, wallets or gift balances. A decline can precede success; pending authorisation and final charge can represent the same amount; merchants can charge as items ship.

Group the lifecycle before calculating¶

Preserve order ID and all transaction, authorisation, reversal and refund references. Ask merchant for reconciliation showing successful, replaced, cancelled and returned events, and compare processor and issuer views.

Do not add every amount without status analysis. Identify different funders where relevant and report attempts separately from successful transfer.