Hello there, this query is related in part to an earlier 'Net of tax issues' thread i started a while back, however that issue was in some respects related on US tax issues, my problem this time is with transactions in our core currency. Below are two formulas i have used to get the Amount Unbilled Net of Tax total in GBP, our primary currency and relatively simple in terms of tax (20% Value Added tax). The first formula was i believe suggested on here, and the second i pulled from Suite Answers, but neither are pulling the desired formula.

i'll take a notable example to illustrate, see below. The first formula is showing a negative figure as it is calculating the full amount of two invoices already issued for this project. As the SO amount is net of tax (highlighted in red) and the full value of the Invoices including tax is £221, 309.49 it's showing a negative amount.