Hello there, @StephenWMidgley. I can help you with your transactions and make sure your book is accurate.
If that transaction is part of your books, you can leave it as is, but if it's not part, you can exclude it. Also, you'll need to check the account because it is possible that the "account for tax" is an expense account. That's why when you transferred it, it shows up as an expense.
However, I would still suggest you refer to your accountant if you're hesitant about it and to ensure the accuracy of your books. Since your accountant knows what's best for your business.
Additionally, you can visit these following articles that will help you in the future :
You can always come back if you have clarification or additional information with you business accounts. I'll be around. Have a good one!