You need to send personalized letters, emails, or labels to many recipients at once. Mail merge in Word lets you create one document and fill in each copy with data from a CSV file. A CSV file stores your recipient information such as names, addresses, and email addresses in a simple table format. This article explains how to connect that CSV file to Word and run a mail merge without errors.
Key Takeaways: Mail Merge Using a CSV Data Source
- Mailings > Start Mail Merge > Step-by-Step Mail Merge Wizard: Guides you through selecting document type, connecting to your CSV file, inserting merge fields, and previewing results.
- Mailings > Select Recipients > Use an Existing List: Opens the file picker where you choose your CSV file and then maps its columns to Word merge fields.
- Mailings > Insert Merge Field: Lets you place individual CSV column values like <
> or < > into your document text.
What Is Mail Merge With a CSV Data Source
Mail merge is a Word feature that produces multiple personalized documents from a single template. The data for each document comes from a list, which can be an Excel file, an Outlook contact list, or a CSV file. A CSV file, short for comma-separated values, is a plain-text format where each line represents one record and each value is separated by a comma. Most email marketing tools, CRM systems, and database applications can export data as CSV.
Before starting the merge, your CSV file must have a header row. The header row contains column names like FirstName, LastName, Email, and Address. Word uses these header names as merge fields. If your CSV file has no header row or uses special characters in column names, the merge may fail or produce blank fields.
Prerequisites for a Successful Merge
You need a CSV file saved on your local drive or a network location. The file should be closed when you connect it to Word. If the CSV file is open in another program such as Notepad or Excel, Word cannot read it. Also ensure your CSV file uses UTF-8 encoding if it contains accented characters or non-English text. UTF-8 encoding prevents garbled names and addresses during the merge.
Steps to Set Up Mail Merge With a CSV Data Source
The following steps use the Mail Merge Wizard, which is the easiest method for first-time users. You can also use the ribbon buttons directly, but the wizard provides clear prompts at each stage.
- Open Word and create a new blank document
Start Word and open a new blank document. This will be your main mail merge template. Do not type any content yet. - Launch the Mail Merge Wizard
Go to the Mailings tab on the ribbon. Click Start Mail Merge and then select Step-by-Step Mail Merge Wizard. A task pane opens on the right side of the Word window. - Select the document type
In the task pane, choose the type of document you want to create: Letters, Email Messages, Envelopes, Labels, or Directory. Click Next: Starting document at the bottom of the pane. - Choose the starting document
Select Use the current document if you want to write your letter or email body now. If you have a pre-written document, choose Start from existing document and browse for it. Click Next: Select recipients. - Select the CSV file as the data source
Choose Use an existing list and then click Browse. In the file picker, change the file type filter to Text Files (prn;txt;csv) or All Files () so your CSV file appears. Select your CSV file and click Open. - Map the CSV data to Word fields
A dialog box titled Mail Merge Recipients appears. It shows all records from your CSV file. You can sort, filter, or uncheck recipients here. Click OK to accept the list. If Word asks to confirm the data source, click OK again. If your CSV header names do not match Word’s default merge fields, click Edit Recipient List then Field Mappings to manually match columns. - Write your document and insert merge fields
Type the fixed content of your letter or email. Where you want personalized information to appear, click Insert Merge Field on the Mailings tab. A list of your CSV column names appears. Click a field name such as FirstName to insert it. Repeat for each field you need. The field appears inside chevrons like <>. - Preview the merged documents
In the wizard task pane, click Next: Preview your letters. Word shows the first merged document with real data from your CSV file. Use the arrow buttons in the task pane to scroll through all recipients. Check that all fields display correctly. - Complete the merge
Click Next: Complete the merge in the wizard. Choose Print to send the documents to your printer, or choose Edit individual letters to create a new Word document with all merged copies. If you selected Email Messages earlier, the wizard prompts you for a subject line and the field containing email addresses.
Common Issues When Using CSV Files in Mail Merge
Word cannot find or open the CSV file
This happens when the CSV file is open in another program, or the file path is too long. Close any program that has the CSV file open. Move the CSV file to a folder close to the root of your drive, such as C:Data. Then repeat step 5 of the wizard.
Merge fields appear blank or show <> instead of data
The CSV header row may contain spaces, punctuation, or special characters. Word may not recognize these as valid field names. Open the CSV file in Notepad and edit the header row to remove spaces and special characters. For example, change First Name to FirstName. Save the file and reconnect it to Word.
Numbers or dates in the CSV appear as garbled text
CSV files store all data as text. If your CSV contains numbers with leading zeros like 00123, Word may drop the zeros. To preserve formatting, open the CSV file in a text editor and wrap the value in double quotes, for example 00123. For dates, use a consistent format such as YYYY-MM-DD to avoid Word misinterpreting the date.
The CSV file is not showing in the file picker
By default, the file picker in Word filters for Excel files. Change the filter to Text Files (prn;txt;csv) or All Files () to see your CSV file. If the file still does not appear, check that it has a .csv extension and is not actually a .xlsx file renamed.
CSV Data Source vs Excel Data Source for Mail Merge
| Item | CSV Data Source | Excel Data Source |
|---|---|---|
| File format | Plain text, comma-separated | Binary, multiple sheets supported |
| Software required to create | Any text editor or spreadsheet app | Microsoft Excel or compatible app |
| Header row requirement | Must be present and free of special characters | Must be present, can contain spaces |
| Data types | All values stored as text | Stores numbers, dates, and text separately |
| Leading zeros preservation | Requires double quotes around the value | Requires formatting column as Text |
| File size limit | No practical limit for mail merge | Excel row limit of 1,048,576 |
| UTF-8 support | Works if file is saved with UTF-8 encoding | Built-in Unicode support |
After completing the mail merge, you can save the merged document as a new Word file for future reference. If you need to reuse the same CSV data source for another mail merge, keep the CSV file in a fixed location and use the Use an existing list option again. To update the data, edit the CSV file and repeat the merge. For advanced control, use the Mailings > Edit Recipient List option to sort recipients by a specific column before merging.