Excel Custom Formula Data Validation Tutorial | Restrict Invalid Employee Codes

In this Excel tutorial, you will learn how to use Data Validation with a Custom Formula to control data entry and prevent invalid employee codes. In this practical example, we create a validation rule that allows only codes in the format: ✅ PR-1001 ✅ PR-5678 and rejects invalid entries like: ❌ AB-1004 ❌ PR1005 ❌ PR-ABCD Topics Covered ✔ Excel Data Validation ✔ Custom Formula Validation ✔ AND Function ✔ LEFT Function ✔ RIGHT Function ✔ LEN Function ✔ ISNUMBER Function ✔ Employee Code Validation ✔ Circle Invalid Data This tutorial is perfect for Excel beginners, students, data entry operators, office professionals, and anyone who wants to improve data accuracy in Excel. 📧 For any questions or Excel-related queries: techlearnstudio93@gmail.com 💬 Feel free to leave a comment below. I reply to every genuine question.