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Clean Vendor Sheet: Excel Cleaning Guide and Best Practices

Learn how to clean vendor sheets in Excel systematically. Discover methods to remove duplicates, standardize formats, validate data, and prepare clean vendor sheets for use.

RowTidy Team
Nov 27, 2025
13 min read
Vendor Sheet, Excel, Data Cleaning, Vendor Management, Best Practices

Clean Vendor Sheet: Excel Cleaning Guide and Best Practices

If your vendor sheets are messy with duplicates, inconsistent formats, and data quality issues, you need systematic cleaning methods. 80% of vendor sheets have data quality problems that cause ERP import failures and operational issues.

By the end of this guide, you'll know how to clean vendor sheets in Excel—removing duplicates, standardizing formats, validating data, and creating clean vendor sheets ready for use.

Quick Summary

  • Remove duplicates - Eliminate duplicate vendor entries
  • Standardize formats - Normalize codes, names, addresses, contacts
  • Validate data - Check emails, phones, tax IDs, addresses
  • Handle missing data - Fill or flag incomplete information

Common Issues in Vendor Sheets

1. Duplicate Vendors

Problems:

  • Same vendor with different codes
  • Duplicate vendor names
  • Multiple entries for same vendor
  • Fuzzy duplicates (similar names)

Impact:

  • Payment errors
  • Duplicate orders
  • Reporting confusion
  • Data integrity issues

2. Inconsistent Formats

Problems:

  • Mixed vendor code formats
  • Inconsistent company name formats
  • Mixed date formats
  • Inconsistent address formats

Impact:

  • System integration problems
  • Lookup failures
  • Reporting errors
  • Data quality issues

3. Invalid Data

Problems:

  • Invalid email addresses
  • Invalid phone numbers
  • Invalid tax IDs
  • Invalid addresses

Impact:

  • Communication failures
  • Compliance issues
  • System errors
  • Processing delays

4. Missing Information

Problems:

  • Missing required fields
  • Incomplete addresses
  • Missing contact information
  • Incomplete financial data

Impact:

  • ERP import failures
  • Processing delays
  • Data quality problems
  • Operational issues

Step-by-Step: Clean Vendor Sheet

Step 1: Backup Original Sheet

Always start with backup.

Create Backup

Method:

  1. Open vendor sheet
  2. File > Save As
  3. Name: "vendor_sheet_backup_2025-11-27.xlsx"
  4. Save in separate location
  5. Original preserved

Why backup:

  • Can't recover if mistakes made
  • Need original for comparison
  • Safety net for errors

Step 2: Remove Duplicates

Eliminate duplicate vendor entries.

Find Duplicates

Method 1: Excel Remove Duplicates

  1. Select data range (including headers)
  2. Data > Remove Duplicates
  3. Check columns:
    • Vendor Code (primary)
    • Vendor Name (secondary)
    • Tax ID (tertiary)
  4. Click OK
  5. Excel shows count removed

Method 2: Formula Detection

=COUNTIF($B$2:$B$1000, B2)>1

Returns TRUE for duplicate vendor codes.

Remove Duplicates

Best practice:

  • Review duplicates before removing
  • Keep most complete record
  • Merge information if needed
  • Document removals

Step 3: Standardize Vendor Codes

Ensure consistent vendor code format.

Choose Standard Format

Recommended:

  • V-001, V-002, V-003
  • Consistent pattern
  • No spaces or special characters (except delimiter)

Apply Standardization

Excel formula:

="V-"&TEXT(VALUE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A2,"V-",""),"V_",""),"vendor_","")),"000")

Steps:

  1. Insert helper column
  2. Enter formula
  3. Copy down entire column
  4. Copy formula column
  5. Paste Special > Values over original
  6. Delete helper column

Step 4: Normalize Vendor Names

Standardize company name formats.

Normalize Legal Suffixes

Standardize:

  • Corp → Corporation
  • Inc. → Incorporated
  • LLC → LLC (keep)
  • Ltd. → Limited

Excel formula:

=SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A2,"Corp.","Corporation"),"Inc.","Incorporated"),"LLC.","LLC"),"Ltd.","Limited")

Standardize Case

Apply Title Case:

=PROPER(TRIM(A2))

Combine:

  1. Apply suffix normalization
  2. Apply case standardization
  3. Remove extra spaces
  4. Verify results

Step 5: Validate Contact Information

Ensure contact data is accurate.

Validate Email Addresses

Check format:

=IF(AND(ISNUMBER(SEARCH("@",A2)), ISNUMBER(SEARCH(".",A2, SEARCH("@",A2)))), "Valid", "Invalid")

Fix invalid:

  • Remove invalid emails
  • Flag for follow-up
  • Contact vendor for correct email

Standardize Phone Numbers

Format:

="("&LEFT(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A2,"(",""),")",""),"-",""),3)&") "&MID(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A2,"(",""),")",""),"-",""),4,3)&"-"&RIGHT(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A2,"(",""),")",""),"-",""),4)

Apply:

  1. Insert helper column
  2. Enter formula
  3. Copy down
  4. Paste as values
  5. Delete helper column

Step 6: Standardize Addresses

Normalize address formats.

Standardize Street Suffixes

Format:

=SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(SUBSTITUTE(A2,"St.","Street"),"Ave.","Avenue"),"Rd.","Road"),"Blvd.","Boulevard"),"Dr.","Drive")

Format ZIP Codes

Standardize:

=TEXT(A2,"00000")

For 5-digit ZIP codes.

Standardize City and State

City:

  • Apply Proper Case
  • Remove abbreviations
  • Standardize spelling

State:

  • Use standard abbreviations (CA, NY, TX)
  • Or full state names
  • Consistent format

Step 7: Validate Tax IDs

Ensure tax identification is correct.

Validate EIN Format

Check:

=IF(LEN(SUBSTITUTE(A2,"-",""))=9, "Valid", "Invalid")

Standardize format:

  • XX-XXXXXXX
  • Remove spaces
  • Ensure proper hyphenation

Apply:

  1. Check format
  2. Standardize if needed
  3. Remove invalid entries
  4. Flag missing tax IDs

Step 8: Handle Missing Data

Deal with incomplete information.

Identify Missing Fields

Find blanks:

  1. Use conditional formatting
  2. Home > Conditional Formatting > Highlight Cells Rules > Blanks
  3. All blanks highlighted
  4. Review missing data

Handle Missing Data

Required fields:

  • Contact vendor for missing data
  • Flag for follow-up
  • Remove if too many missing required fields

Optional fields:

  • Fill with "N/A" or "Unknown"
  • Leave blank if acceptable
  • Document missing data

Step 9: Standardize Financial Information

Normalize payment terms and currency.

Standardize Payment Terms

Format:

  • Net 30, Net 60 (standard)
  • Remove variations
  • Ensure consistency

Apply:

  1. Review current formats
  2. Choose standard format
  3. Replace variations
  4. Verify consistency

Standardize Currency

Use ISO codes:

  • USD, EUR, GBP
  • Consistent format
  • Validate codes

Step 10: Final Validation

Quality check cleaned vendor sheet.

Validation Checklist

Verify:

  • No duplicates
  • Vendor codes standardized
  • Vendor names normalized
  • Contact info validated
  • Addresses standardized
  • Tax IDs validated
  • Missing data handled
  • Financial info standardized
  • Ready for use

Test Import

Before finalizing:

  • Test ERP import (if applicable)
  • Verify data quality
  • Check for errors
  • Confirm completeness

Real Example: Cleaning Vendor Sheet

Before (Messy Vendor Sheet):

Issues:

  • 200 duplicate vendors
  • Inconsistent vendor codes (V-001, V001, V_001)
  • Mixed company name formats
  • 150 invalid email addresses
  • Incomplete addresses
  • Missing tax IDs
  • Inconsistent payment terms

After (Clean Vendor Sheet):

Improvements:

  • ✅ Duplicates removed (200 eliminated)
  • ✅ Vendor codes standardized (V-001, V-002 format)
  • ✅ Company names normalized
  • ✅ Emails validated and fixed
  • ✅ Addresses complete and standardized
  • ✅ Tax IDs validated
  • ✅ Payment terms consistent
  • ✅ All formats standardized
  • ✅ Ready for ERP import

Result:

  • Clean vendor sheet: 1,800 unique vendors
  • 100% format consistency
  • 95% data completeness
  • Ready for use

Best Practices for Cleaning Vendor Sheets

Do's

✅ Do backup first - Always save original
✅ Do remove duplicates first - Before standardization
✅ Do standardize systematically - One format at a time
✅ Do validate thoroughly - Check all data
✅ Do handle missing data - Fill or flag appropriately
✅ Do test before finalizing - Verify quality

Don'ts

❌ Don't skip backup - Risk data loss
❌ Don't standardize duplicates - Waste of time
❌ Don't mix cleaning steps - Follow order
❌ Don't skip validation - Quality matters
❌ Don't ignore missing data - Handle appropriately
❌ Don't export untested - Verify first

Mini Automation Using RowTidy

You can clean vendor sheets automatically using RowTidy.

The Problem:
Cleaning vendor sheets manually is time-consuming:

  • Removing duplicates
  • Standardizing formats
  • Validating data
  • Handling missing information

The Solution:
RowTidy cleans vendor sheets automatically:

  1. Upload vendor sheet - Drag and drop Excel file
  2. AI analyzes sheet - Detects all issues
  3. Auto-cleans data - Removes duplicates, standardizes formats
  4. Validates data - Checks emails, phones, tax IDs
  5. Exports clean sheet - Get cleaned vendor sheet

RowTidy Features:

  • Duplicate removal - Finds and removes duplicate vendors
  • Format standardization - Codes, names, addresses, contacts
  • Data validation - Emails, phones, tax IDs, addresses
  • Missing data handling - Flags or fills as appropriate
  • ERP-ready export - Formats for system import

Time saved: 3-6 hours manual → 10 minutes automated

Clean vendor sheets automatically with RowTidy. Try RowTidy's vendor sheet cleaning →

FAQ

1. How do I clean a vendor sheet in Excel?

Remove duplicates first, then standardize vendor codes, normalize vendor names, validate contact information, standardize addresses, validate tax IDs, handle missing data, standardize financial info, then validate quality.

2. Should I backup vendor sheet before cleaning?

Yes, always. Backup original sheet before any cleaning. Can't recover if mistakes made without backup.

3. How do I remove duplicates from vendor sheet?

Use Excel Remove Duplicates (Data > Remove Duplicates) checking Vendor Code, Vendor Name, Tax ID columns. Review before removing, keep most complete record.

4. How do I standardize vendor codes?

Choose standard format (V-XXX recommended), use Excel formula to convert all codes, apply consistently, verify uniqueness.

5. How do I validate email addresses in vendor sheet?

Use formula to check for @ symbol and valid domain, or use RowTidy for automatic validation. Remove or flag invalid emails.

6. Should I clean vendor sheets regularly?

Yes. Clean quarterly minimum, monthly recommended for active vendor management. Clean when receiving updates or noticing data quality issues.

7. Can I automate vendor sheet cleaning?

Yes. Use RowTidy to automatically clean vendor sheets: remove duplicates, standardize formats, validate data, handle missing information.

8. What format should vendor codes be?

Standardized format (V-XXX recommended). Consistent throughout sheet. No spaces or special characters except delimiter.

9. How do I handle missing data in vendor sheets?

Contact vendor for missing required fields, use "N/A" for optional fields, flag for follow-up, remove if too many missing required fields.

10. How long does it take to clean vendor sheets manually?

Depends on size: small (500 vendors) = 1-2 hours, medium (2,000 vendors) = 3-6 hours, large (10,000+ vendors) = 1-2 days. RowTidy cleans in minutes.

Related Guides

Conclusion

Clean vendor sheets by removing duplicates first, then standardizing formats (codes, names, addresses, contacts), validating data (emails, phones, tax IDs), handling missing information, and ensuring data quality. Follow systematic approach for efficient cleaning. Use tools like RowTidy to automate vendor sheet cleaning and save time while ensuring data quality.

Try RowTidy — automatically clean vendor sheets and prepare them for use.