You paid the contractor — through your bank app, a transfer, a QR scan, whatever. Marking the invoice paid in Hemma is the one bookkeeping step left. It takes a tap, and once it is done the contractor's outstanding total drops, the Files filters update, and the paid date is on the record.
Open the invoice from Files or from the contractor view. On the right of the detail page, the Payment card holds everything related to paying:

Tap Mark as paid. A small confirmation dialog opens — that one extra step is on purpose, so a stray tap in a list view does not flip the state without you noticing. Confirm, and three things happen in sequence:
The "method" is recorded automatically based on what you did just before. If you tapped the QR open, it is recorded as qr. If you copied the IBAN to your clipboard, copy. If you used the browser share sheet, share. If you did none of those — for instance, you paid days ago in your bank app and are catching up — it stays manual. You do not have to pick; Hemma watches.
If you marked something paid by mistake, the Mark as unpaid button appears on the paid card. Tap it and the state reverses — the payment record is removed, the date clears, the outstanding total recomputes. There is no time limit.
Credit notes are not "paid" — the money flows the other way. When Hemma recognises a document as a credit note, the Payment card shows a credit-note panel instead of a Mark-as-paid button, with the negative amount and a short note. There is nothing to do; it counts against the contractor's balance automatically.
Can I record a partial payment? Not in this version. Each invoice is either paid or unpaid. If you paid half now and half later, mark it paid when the second instalment lands. If you need a paper trail of two payments, leave a note on the invoice.
Where does Hemma get the IBAN, amount, and reference from? From the invoice itself — the AI extracts them when the document arrives. If something was extracted wrong, the inline pencil icons on the Payment card let you correct it before paying. See reviewing and correcting what the AI extracted.
Does marking paid update my budget? No — the Invoiced column on the budget reflects what was linked, not what was paid. Paying changes the contractor's outstanding total, not the budget total. See linking an invoice or quote to a budget line for the budget flow.
Who can mark paid? Anyone on the project. The action is logged so the rest of the team can see who confirmed it.
Can I change the paid date later? Yes — undo, then mark paid again. The new timestamp is the new paid date.