Please Note: This article is written for users of the following Microsoft Excel versions: 97, 2000, 2002, and 2003. If you are using a later version (Excel 2007 or later), this tip may not work for you. For a version of this tip written specifically for later versions of Excel, click here: Ensuring Unique Values in a Column.
Written by Allen Wyatt (last updated September 14, 2022)
This tip applies to Excel 97, 2000, 2002, and 2003
When you are entering information in a worksheet, you may want to ensure that the data being entered is actually unique for a particular column. For instance, if you are entering a series of invoice numbers in column D of a worksheet, you may want to ensure that you don't enter the same invoice number twice.
There are a couple of ways that you can approach such a problem. If you are always entering your new information at the bottom of a column, you can use Excel's data validation feature to make sure that whatever you are entering in the current cell does not match anything higher up in the column. Simply follow these steps:
Figure 1. The Data Validation dialog box.
Please Note:
This article is written for users of the following Microsoft Excel versions: 97, 2000, 2002, and 2003. If you are using a later version (Excel 2007 or later), this tip may not work for you. For a version of this tip written specifically for later versions of Excel, click here:
=MATCH(D1,$D:$D,0)=ROW(D1)
If you may be entering data anyplace within column D, and you want to know if you are entering a value that is elsewhere in the column (above or below the current cell), then you can follow the above steps, but use this formula in step 4:
=COUNTIF($D:$D,D1)<2
ExcelTips is your source for cost-effective Microsoft Excel training. This tip (2650) applies to Microsoft Excel 97, 2000, 2002, and 2003. You can find a version of this tip for the ribbon interface of Excel (Excel 2007 and later) here: Ensuring Unique Values in a Column.
Dive Deep into Macros! Make Excel do things you thought were impossible, discover techniques you won't find anywhere else, and create powerful automated reports. Bill Jelen and Tracy Syrstad help you instantly visualize information to make it actionable. You’ll find step-by-step instructions, real-world case studies, and 50 workbooks packed with examples and solutions. Check out Microsoft Excel 2019 VBA and Macros today!
Want to control what users put into a cell? It's easy to do using a feature called data validation, as described in this tip.
Discover MoreWhen using data validation, you might want to have Excel display a message when someone starts to enter information into ...
Discover MoreIt is not unusual to use Excel to gather the answers to users' questions. If you want your users to answer your questions ...
Discover MoreFREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."
2020-04-02 11:31:29
Nigel Horne
Give me a heck of a lot of false positives. Doesn't work.
Got a version of Excel that uses the menu interface (Excel 97, Excel 2000, Excel 2002, or Excel 2003)? This site is for you! If you use a later version of Excel, visit our ExcelTips site focusing on the ribbon interface.
FREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."
Copyright © 2025 Sharon Parq Associates, Inc.
Comments