Excel Data Validation – Custom Rules, Logic & Error Alerts | Data Analysis Series (Part 3)

Welcome to Part 3 of the Data Validation Series! In this session, we go beyond simple validation and learn how to enforce custom rules using Excel’s logic-based validation features. You’ll learn: ✅ How to use Custom Validation Formulas ✅ Enforcing text length limits ✅ Restricting inputs using logical operators ✅ Validating based on another cell (dependency logic) ✅ Preventing duplicate entries using powerful formulas ✅ Creating smart rules using: LEN() ISNUMBER() COUNTIF() AND() / OR() DATE() checks ✅ Setting Input Messages & Error Alerts to guide users Real-world example included: ⭐ Restrict entry only if “Status = Active” ⭐ Prevent duplicate IDs ⭐ Allow only emails that contain “@company.com” By the end of this video, you’ll be able to design professional-grade validation rules that eliminate errors and improve data quality. 📈 Next up: Data Validation – Part 4: Dependent Drop-Down Lists (Advanced)