Prevent duplicates before they happen by combining a simple function with data validation. Excel has built-in tools to expose and even delete duplicates, but they work on existing data after the fact.

Learn how the new Excel Copilot function simplifies data cleanup, automates tasks, and boosts productivity for analysts and beginners alike.

How to Use Excel to Show Only Duplicate Values. Business issues such as incorrect transactions, data entry errors, technical glitches and poor system design may cause duplicate values in your data ...

Here are four ways to express dates using data validation: literal values, input values, a list, and formulas. I’m using Excel 2016 (desktop) on a Windows 10 64-bit system.