Speeding Up Mail Merges

The Mail Merge tool in Word can be very helpful in combining information from a data source (such as names or addresses) with information in a standard document (such as letters or labels). If you have many, many records in your data source, though, the mail merge might not run as quickly as you like.

For example, let's say you are merging a large amount of data (10,000 or 20,000 records) with a single-page document to create a form letter. The most common method of doing a merge is to create a new document that contains the merged information. As each record is fetched and processed, a new page is added to the merged document. If you have 20,000 records in your data source, this means you are attempting to create a 20,000 page document! Word won't theoretically choke on such a huge document, but it may slow to a crawl depending on the capabilities of your computer.

There are a few things you can do to help speed things up. First of all, make sure you are using Draft view before you do the merge and that you turn off background repagination. This should stop Word from trying to repaginate the document during the merge process. You will also want to turn off any anti-virus software you use, or at least configure it so that it won't scan Word documents for viruses.

Another obvious thing to try is to not merge to a new document, but merge directly to the printer. Since mail merging is still a memory-intensive operation, you may still notice slowdowns while merging. In this case, you should apply any or all of the following items, which can generally conserve memory use on a PC:

• Reboot your PC just before doing the mail merge so all memory resources are available.
• Turn off any screensaver on your system. The screensaver timer and display routines use up memory. Also you don't want it cutting in during the merge.
• Turn off any wallpaper on your system. You can also reduce screen colors and screen resolution.
• Since any huge memory use by Windows results in information being written to the hard drive, regularly run Scan Disk and Defrag.
• Don't do anything else on the computer while it is doing the mail merge; don't have any other applications open.
• Remove software from the Startup folder, or close them. Close what you can from the System Tray.
• Reduce the number of shortcut icons on the desktop. Put them in folders if you need them to stay on the desktop.

After trying all these things, if you still can't get a mail merge to finish quickly, you will need to either add more memory or merge fewer records. In other words, instead of doing a single mail merge of 20,000 records, do ten mail merges of 2,000 records each. If I were doing this and my source data were in an Excel workbook, I would make ten copies of the workbook and make sure that each copy contained only 2,000 records. Then, in Word, I would change the data source for each running of the merge process.

WordTips is your source for cost-effective Microsoft Word training. (Microsoft Word is the most popular word processing software in the world.) This tip (10774) applies to Microsoft Word 2007, 2010, 2013, 2016, 2019, Word in Microsoft 365, and 2021. You can find a version of this tip for the older menu interface of Word here: Speeding Up Mail Merges.