Warning of duplicate values ​​in Excel - Warning of data duplication

Microsoft Excel gives you lots of useful features to help your data entry work best. One of those features is the duplicate value warning feature.

For many important data that do not allow data to be duplicated, the use of duplicate value warning is essential. To know how to set up duplicate value alerts in Excel, you can follow the article below.

The article shows you how to warn duplicate values ​​in Excel 2013, with Excel 2007 and 2010 you do the same.

Step 1: Select the data area to be alerted for duplicate values, next you select the Data tab on the Ribbon.

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Step 2: In the Data Tools section, select Data Validation -> Data Validation .

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Step 3: In the Settings tab, select Custom in Allow , and enter the formula in the Formula section . For example, if you want to warn duplicate values ​​in C5: C11, then you enter the formula = COUNTIF ($ C $ 5: $ C $ 11, C5) = 1 .

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Step 4: Select the Error Alert tab , here you select the type of alert in the Style section , enter the warning title in the Title section , enter the warning content in the Error message section . Then you click OK to finish.

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So when you enter the duplicate content will receive a warning message of duplicate values.

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Thus, with the function of warning of duplicate values ​​of Data Validation in Excel, you can enter data quickly without worrying about data duplication. Good luck!