The question of what comes out of your bank account is completely separate. When you pay off the purchase invoice, simply pay the amount the supplier charged you, inclusive of VAT. In the first screen shot of your last post, the total was 115.56, which is what the supplier expects to receive. The payment involves no tax codes. Your supplier will be happy. Your tax authority will know you paid 19.26 in VAT, because that is what your supplier will report. And that is what you will report, because your tax liability account will be reduced by the amount posted because of the rounding line, even though it does not show on the specific purchase invoice. (Remember, purchase invoices only serve to record your suppliers’ sales invoices to you. They do not go anywhere outside the company.)
The fact that the sub-total for the line items is off by a penny will not matter, because that number appears only on the sales invoice. It is not actually used to calculate your income—the postings to your income accounts are done from the individual line item amounts. And the difference occurs only in the 100% tax rounding line item, which only affects your tax liability account.
Another way to handle this is to enter tax-inclusive prices, adjusting them to match the supplier’s total. That method is described in this Guide: https://www.manager.io/guides/9499.
If you are worried about what an auditor might think, remember two facts:
- Auditors are well aware of this situation. In fact, most tax regulations explicitly allow both methods. And they’ve seen it many times before. Since your VAT calculations will match your supplier’s, the auditors will not care what a sub-total says you paid for the items. If anything, they will check what the line item says you paid for an item.
- Your tax liability will be the net of many transactions, both buying and selling. There is an excellent chance the rounding differences will balance out to zero. Even if they don’t, they will likely be minimal. If you are reporting in whole currency units, they will probably not even be visible.
So do not go the second step of your last screen shot. Adjusting the adjustment hardly makes sense. And your VAT worksheet won’t work with it anyway.