Written by Allen Wyatt (last updated May 24, 2025)
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.
=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.
Best-Selling VBA Tutorial for Beginners Take your Excel knowledge to the next level. With a little background in VBA programming, you can go well beyond basic spreadsheets and functions. Use macros to reduce errors, save time, and integrate with other Microsoft applications. Fully updated for the latest version of Office 365. Check out Microsoft 365 Excel VBA Programming For Dummies today!
It is not unusual to use Excel to gather the answers to users' questions. If you want your users to answer your questions ...
Discover MoreWant to have a small help screen pop up when a user selects a particular cell? This can be done by using data validation, ...
Discover MoreWant to create an easy drop-down list? You can do so by using the data validation features of Excel.
Discover MoreFREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."
There are currently no comments for this tip. (Be the first to leave your comment—just use the simple form above!)
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