I've created and issued two invoices in the square app, both of which have been paid by the customer through cash transfer. However, as I could not see an option to mark them as "paid" in the app, I cancelled the invoices despite them being paid to avoid constant reminders.

I realise now I can actually mark invoices as paid in the online browser so now would like to consolidate my records by "undoing" the cancelled invoices and marking them as paid. However, I've been told that it's not possible to actually undo cancelled invoices. This presents a problem when the UX/UI interface on the app *appears* as having limited options to mark the invoice as paid?

Further, considering you can't duplicate an invoice with the same invoice number, it becomes hard to record which invoices are paid and which are "re-issued", not to mention annoying for the buyer if they keep getting notifications of re-issued invoices. 

May I suggest either:

1 - allowing duplication of cancelled invoices with the same invoice details (including invoice number).

2 - allowing the undoing of cancelled invoices.

3 - allowing a feature in the app for marking invoices as paid if they have been paid using other methods (such as cash or bank transfer). Given this feature allowable online, there doesn't seem to be a reason to not have it allowed in the app.