## Forum Discussion

Can you please let me know how you found the error so that if it happens in the future I I can manage it.

With many thanks, Mabby

Mabby Plain luck, I guess. On the Formulas ribbon, I selected "Show formulas", so that I could see what you really have in all the cells. I noticed quite a few inconsistent formulae, but the one in T269 stood out. There's not really much more to it.

With respect to inconsistent formula, you may want to consider looking over columns E and F in particular. Quite a lot happening there which is bound to create problems. The screenshot below shows the content of just a small area. Notice that column E has formulae and constants and column F mostly has SUM formulae, and then suddenly just a reference to one cell. Better to devise a rule that allows you to calculate GST with a consistent formula (if possible) and use consistent formulae in columns that sum two other columns

With regard to the formulae themselves, * =PRODUCT(D249,1/11)* would be easier to read (in my opinion at least) if you would use

*. Similarly,*

**=D249/11***could simply be written like*

**=SUM(D249,-E249)***.*

**=D249-E249**