Why does my mail merge show field codes instead of actual data?

The field codes aren't being converted to actual values. Press Ctrl+A to select all, then Ctrl+Shift+9 (or Ctrl+Shift+F9) to convert field codes to actual values. If that doesn't work, rebuild the merge fields.

What does 'data source is not accessible' mean?

Word can't find or open your data source file (Excel, Access, CSV, etc.). Verify the file still exists at the location you specified. If you moved it, re-open Mail Merge > Select Recipients and point to the new location.

Can I use different data sources for different mail merges?

Yes. Each mail merge document is independent. When you start a new mail merge, you select which data source to use. Different documents can use different data sources.

Fix: Word Mail Merge Errors and Failures

The Problem

Your Word mail merge isn’t working—it shows errors, doesn’t merge properly, displays field codes instead of data, or fails to complete. You need to fix the merge to produce the intended output letters, labels, or documents.

Quick Fix

Verify your setup:

Check that your data source (Excel, CSV, Access) has headers in the first row
Go to Mailings > Select Recipients > Use Existing List
Point to your data source file
Go to Mailings > Insert Merge Field and verify field names match your data
Click Mailings > Finish & Merge > Edit Individual Documents to test

Step-by-Step Solution

Method 1: Verify Your Data Source Format

Most merge problems stem from incorrectly formatted data sources.

Step 1: Open your data source (Excel file, Access database, or CSV file) in its native application.

Step 2: Check the first row—it must contain column headers exactly as you want them referenced in Word.

Step 3: For example, if you want to merge “FirstName,” the column header must be exactly “FirstName” (case-sensitive in some cases).

Step 4: Ensure there are no blank rows in the header row.

Step 5: Check that all data rows have values in the key columns you’re merging.

Step 6: Remove any entirely blank rows at the bottom of the data.

Step 7: Save and close the data source.

Step 8: Now return to Word and retry the merge.

Method 2: Set Up Mail Merge from Scratch

Starting fresh often fixes configuration issues.

Step 1: Open the Word document you want to use as your mail merge template (or create new one).

Step 2: Go to Mailings tab in the ribbon.

Step 3: Click “Start Mail Merge.”

Step 4: Select the type of merge:

Letters (for letters to multiple recipients)
Email messages (for email merge)
Envelopes (for address labels)
Labels (for mail labels)
Directory (for catalogs or lists)

Step 5: Click “Select Recipients.”

Step 6: Click “Use Existing List.”

Step 7: Navigate to your data source file and select it.

Step 8: Click Open.

Step 9: If a dialog appears asking to select a table/sheet (for Excel or Access), select the appropriate one.

Step 10: Click OK.

Step 11: Your data source is now connected.

Method 3: Insert Merge Fields Correctly

Field names must exactly match your data source columns.

Step 1: Position your cursor where you want the first data to appear (e.g., after “Dear ” for a greeting).

Step 2: Go to Mailings > Insert Merge Field.

Step 3: A dropdown shows available fields from your data source.

Step 4: Click the field you want to insert (e.g., FirstName).

Step 5: The field code appears: <>

Step 6: Repeat for other fields you need (<>, <

>, etc.).

Step 7: Important: If a field name doesn’t appear in the dropdown, it doesn’t exist in your data source. Go back and check column headers in your data source file.

Step 8: If you’re manually typing field codes, they must be exactly spelled and case-sensitive.

Method 4: Preview and Test the Merge

Before merging all records, test with sample data.

Step 1: With your merge document open and fields inserted, go to Mailings.

Step 2: Click “Preview Results.”

Step 3: This shows what the first merged document will look like using actual data.

Step 4: You’ll see “Record 1 of [total number]” at the top.

Step 5: Use the arrow buttons to preview different records.

Step 6: Check that:

Fields are populating with data
Data looks correct and in right format
No errors appear

Step 7: If something looks wrong, click “Preview Results” again to hide the data and return to edit mode.

Step 8: Fix any issues (field placement, formatting, data source problems).

Step 9: Once preview looks good, proceed to complete merge.

Method 5: Fix “Data Source Not Accessible” Error

This error means Word can’t locate your data source file.

Step 1: Go to Mailings > Select Recipients.

Step 2: Click “Use Existing List.”

Step 3: Navigate to where your data source file actually is.

Step 4: Verify the file exists and hasn’t been moved or renamed.

Step 5: If the file has moved, navigate to the new location and select it.

Step 6: If the file has been renamed, locate the new filename.

Step 7: Click Open to reconnect.

Step 8: Now the merge should work with the correctly located data source.

Method 6: Handle Special Characters in Data

Special characters can cause merge failures.

Step 1: Check your data source for special characters like:

Curly braces { }
Angle brackets < >
Quotation marks ” ”
Ampersands &

Step 2: These characters can interfere with field codes.

Step 3: Replace them with neutral alternatives:

Instead of ”&” use “and”
Instead of quotation marks use apostrophes or different punctuation

Step 4: Save the data source with corrections.

Step 5: Retry the merge.

Method 7: Convert Field Codes to Values

If your merged document shows field codes (<>) instead of actual values, they need converting.

Step 1: Select all text in the document (Ctrl+A).

Step 2: Press Ctrl+Shift+9 (or Ctrl+Shift+F9 in some Word versions) to convert field codes to values.

Step 3: The <> codes will convert to actual names.

Step 4: If the shortcut doesn’t work, try: right-click > Update Field.

Step 5: Select “Update all fields” and click OK.

Method 8: Complete the Merge

Once everything is tested and working, finalize the merge.

Step 1: Go to Mailings > Finish & Merge.

Step 2: Choose your merge output:

“Edit Individual Documents” — creates new document with all merged records
“Print Documents” — prints merged documents directly
“Send Email Messages” — for email merges

Step 3: If you select “Edit Individual Documents,” choose whether to merge all records or specific ones.

Step 4: Click OK.

Step 5: A new document is created with all merged records.

Step 6: Save this new document with a clear name (e.g., “Merged_Letters_March2026.docx”).

Why This Happens

Data source problems: Headers missing, blank rows, inconsistent column names.

Field codes mismatched: Field names in merge document don’t match data source column names.

File path broken: Data source moved or renamed after merge setup.

Special characters: Unusual characters in data interfere with merge.

Excel frozen panes: If your Excel sheet has frozen panes, Word might not read headers correctly.

Wrong sheet selected: In Excel files with multiple sheets, the wrong sheet might be selected.

How to Prevent It

Prepare data source carefully: Create a clean, properly formatted data source with clear headers.

Test before mass merge: Always preview several records before merging all.

Keep data source and template together: Store in the same folder so links don’t break.

Document field names: Note what fields you’re using so you don’t forget.

Create backup: Save a backup of your template before doing extensive merges.

Still Not Working?

Try different data format: Convert Excel to CSV and retry—sometimes simpler formats work better.

Check field syntax: Ensure merge field names are spelled exactly as they appear in headers (including capitals).

Use Mail Merge Wizard: Instead of manual setup, try Mailings > Start Mail Merge > Step-by-Step Mail Merge Wizard for guided process.

Test with simpler data: Create a test with just 2-3 rows and 2-3 columns to isolate issues.

Contact Microsoft Support: For persistent issues, Microsoft Support can help troubleshoot complex merge setups.