This article explains the management of payments on invoices when they have been generated manually, outside a reservation.
Invoices created manually: as invoices created from invoices > invoices are not linked to a reservation, it will be possible to log a payment from the invoice only.
To log a payment, click on "..." on the corresponding line, then click on Details :
Then click on Record a payment:
Select the date, amount, and payment method:
Finally, click on Add Payment and the payment status of the booking will be updated.
Once an invoice is paid, it cannot be modified anymore.