Hi @Jules_K
If the sale was picked up in the VAT return, then it’s been tagged somewhere. It may just be that it was tagged to the wrong place and needs to be journalled for it to show correctly.
For more information on journals, please check out the following post: Journals
To try and find the correct code that you should be posting to, check out your chart of accounts: The Chart of Accounts
I hope this helps, but if you have any further questions, please don’t hesitate to ask.