Closing Old Accounts, unallocated entries, different VAT codes

SOLVED

Hi All

Another, whats the best way to do something that should've been done right 5 years ago question.

I want to close an old customer account, but I can't because there are open entries.

I have an invoice from 2018, T9 tax code which was paid at the time, minus bank charges

I have a credit for those bank charges in 2020, but on T0,

When I try and match them, I get a mismatch error

We'll just gloss over why they are those tax codes, there was no VAT

I can edit the Credit to be a T9, but that gives the closed period warning
Or
I can create a new T0 invoice to match against the credit note, and a new T9 credit to match against the balance of the invoice?

I suspect I am going to have a lot of these so if there is a "correct" way I'd like to jump on it

Kind regards

Dominic