Adjusting an invoice will affect which account the amount was booked to. There is no effect if the invoice is paid, either. So that's a question for your external accountant, since if you've already sent a trial balance they wouldn't want you making changes.

What you should almost never do, is to delete a paid invoice. Adjustments where the total is the same are mostly harmless.

To keep it from happening again, set up a recurring transaction for each recurring supplier invoice.

If you use recurring transactions, and regularly check the Daily Business Manager, you'll catch things like your cell company 'accidentally' switching you to E-bill so you stop seeing paper statements. Also, these recurring transactions can be used in cashflow reports.

Yes I figured that anything from last year should not be touched. What about April? Should I just keep a note for next year so they do the transfer to the correct account? Or would you suggest doing some kind of journal entry?

For current year transactions, it's usually best to open, adjust, and post them.

If you do a separate journal entry, someone can still come across the original (wrong) transaction and 'fix' it again.

But if it's already paid it wont let me adjust right?

What happened when you tried it?

Never mind it's me being silly it did work. Thanks guys for your help :)