How can I apply sales tax / invoices

Question

I'm just getting to know numbers (and iwork),
how can I apply sales tax to only the desired lines I want with the invoice templates?

Answer 1

Linda Linda wrote:
how can I apply sales tax to only the desired lines I want with the invoice templates?
One way is with the addition a of a checkbox column to the template to indicate taxable items & the addition of a separate column for the tax, which you can subtotal separately & add to the untaxed "Cost" column. The formula for the tax column would use an IF statement & the fact that a checked box represents the "true" condition & an unchecked one the "false" condition. The formula would be something like:
=IF(D, $C$11*F, 0)
where $C$11 is a reference to the template's tax rate cell, "D" is the column with the checkbox format, & "F" is the Cost column, here "bumped" to the right from its original column by the addition of the new columns. (Yvan's ROUND formula can be applied to the individual item taxes or to the tax subtotal, depending on what is customary or required by law.)
A more sophisticated, automated approach could involve a separate table in a separate sheet listing the taxable (or non-taxable) item descriptions & a formula to calculate the truth value from that instead of with a checkbox column. This would allow you to avoid showing a checkbox column in the submitted invoice without hiding it.
Note that in any approach, you can hide columns (or rows) you don't want to be seen or printed.
Message was edited by R C-R to explain the "F" reference.