This document covers the reasons for performing consistent maintenance on your QuickBooks files.


One of the best parts of having an online backup service is that your data is always backed up—painlessly—every night. So now you never need to use the backup routine in QuickBooks for making periodic backups, right? Wrong!


Best practices in maintaining a healthy QuickBooks file still dictates performing a manual backup on a regular basis. Not using the actual backup process in QuickBooks can lead to trouble with your data file down the road. The reason is just three little letters—TLG. The .TLG file is one of several files that QuickBooks creates every time you open your company file in a new place.


The main file has the extension .QBW. Then there is a .QBW.ND file which helps the QuickBooks Database Server manage access to the file. The .QBW.TLG file stands for Transaction Log, and it's there to help recover data in case your main file gets corrupted somehow. All the transactions created in your company file are duplicated in the .TLG file as a kind of backup. Theoretically, Intuit Data Services can use this to recover corrupted data.

The problem is that the .TLG file grows exponentially faster than the actual .QBW file, leading to some really, really big files (much larger than the actual .QBW file). Below is a really bad example—the company file is 479 MB, but the .TLG file is 25GB!


The problem comes because QuickBooks is trying to write to this huge .TLG file in addition to doing its real work, and if it's too big the computer just runs out of memory. This causes errors and unexpected shutdowns in QuickBooks. In the case above, the company wasn't able to make a backup and had to call Intuit support during off-hours.


So how do we prevent this growth? It's really quite simple. On a routine basis, run the Backup routine from the File menu in QuickBooks and make sure to choose Complete Verification.

Note that this will have to be done in single user mode; if you are in multi-user mode the Complete Verification choice will be grayed out.


This process ensures that the data file is healthy and QuickBooks then resets the .TLG file. It's as if QuickBooks is saying, "Okay, we don't need all this excess insurance. Let's lose it." If you do this on a monthly basis, not only will you have a nice archival copy of your month for historical purposes, but you will be ensuring that your QuickBooks company file is healthy, and stays that way. This must be done manually, the automated backup routine within QuickBooks does not reset the .TLG file.


If you haven't been doing this however, and you have a really big .TLG file already, it will actually prevent QuickBooks from being able to Verify and Backup the file. In this case, the best thing to do is to move or rename the .TLG file to something like "filename.TLG.OLD". This allows you to proceed with the Complete Verification and backup of your file. Once this has been done successfully, you can delet the old .TLG file. That's what happened in the case above. We moved that monstrous .TLG file to the desktop and were then able to successfully Verify the file and back it up.

It sure felt good to drag that monster to the Recycle Bin!


Take a look at your .TLG file. Is it bigger than the company file itself? If so, then it's probably time to instate regular manual backups as part of your company's accounting procedures.