What Is Mail Merge in Word?

Mail merge is a Microsoft Word tool that allows you to easily modify one part of a document with unique data elements.

How Mail Merge Works

Mail merge works by linking a database to your document. The database contains the unique elements (Sue, Jack, Peggy, etc.) and the document is your letter, invoice, label set, or another file.

Mail merge saves you time and effort because it automates the process of entering one unique piece of data into a document. For example, say you want to write a holiday letter and send it to 20 people. You can write the letter and create a mail merge to print it with 20 different salutations (Dear Sue, Dear Jack, Dear Peggy, etc.).

Mail Merge Uses

You can use mail merge to create any type of printed document, as well as electronic documents. Here are some examples of document types:

• Catalogs
• Inventories
• Invoices
• Labels
• Envelopes
• And, of course, letters

In addition to saving you time, mail merge can boost the effectiveness of the documents you create. For example, by customizing letters with specific names or other elements, you present a polished, personal image.

Anatomy of a Mail Merge

As mentioned above, mail merge consists of two main parts: the document and the data source or database.​ Word simplifies your work by enabling you to use other Office applications such as Excel or Outlook as data sources.

If you have the full Office suite, it's easy and convenient to use one of those applications as your data source. For example, you can use contacts that you've already entered into Outlook, saving yourself the trouble of re-entering them in Word. An existing Excel spreadsheet gives you even greater flexibility with your data. 

Setting Up a Mail Merge

A mail merge may seem complicated and complex. However, Word simplifies the setup for common uses with wizards that walk you through the process of linking your document to a database.

Generally, you can complete the entire process in fewer than 10 steps, including finding and correcting errors. That's fewer than preparing your document manually would take and with much less time and hassle.