Hey there, @Ptonjalken.

I'm happy to take a look at this with you today.

If the Square payment synced as an unapplied payment, it should just link it to the invoice through receive payment.

Alternatively, if it was synced as a deposit, you can post it to AR account and link it to the invoice. 

If it's already synced as a sales receipt you can delete the related invoice instead and keep the sales receipt since that's already a sales transaction and we don't want to double post the income account.

Has this happened with Square transactions in the past, or is this the first one you've received?

I'd love to hear how this goes! Please reach back out if you have remaining questions on this or anything else.