Excel validation lists avoid blanks and errors with TOCOL(ignore) plus FILTER; the spill range stays stable across worksheets.

Build flexible Excel functions that automatically handle blanks, defaults, and overrides without messy nested IFs.

Calculating sales tax on prices is something you don't have to worry about if you use Excel. You can add a formula to the spreadsheet you use for invoices, bills of sale or quotes, and that's the end ...