Use Excel data validation to prevent duplicate values in a column Your email has been sent Prevent duplicates before they happen by combining a simple function with data validation. Excel has built-in ...

Business issues such as incorrect transactions, data entry errors, technical glitches and poor system design may cause duplicate values in your data sets. Duplicate values can exist across rows or in ...

Excel's data validation feature is more versatile than you might think. Learn how to use literal values, input values, list values, and even formulas to restrict input date values using data ...