Part of your QuickBooks company data is the TLG file. It’s not something you normally are aware of, but in some situations it can be a very important file.

The transaction log file (TLG for short) is maintained automatically by QuickBooks as part of your data. The file resides in the same folder as your main QBW file, and has the same file name. But it has a .TLG extension. In transaction-intensive businesses, the file can become quite large — 1GB or bigger.

Whenever you post a transaction in your company file, the TLG file is updated. And that is why it is sometimes a very valuable file.

We sometimes talk to people who have lost their current data file — it either got deleted somehow, or is so badly damaged it is unusable and unfixable.

But if they have a good backup — even if it is old — and a good current TLG file, we can take the old backup and bring it to current status by applying the missing transactions we can get out of the TLG file.

It’s one method we use for QuickBooks data repair.

I am working with a customer today who has this exact scenario, so I thought I’d briefly write about it.

p.s. We occasionally hear of users being instructed to delete their TLG file. Don’t ever do that without copying it to a different folder or drive first. You might need it sometime!

21 thoughts on “The Hidden Value of the QuickBooks TLG file

  1. I have noticed that even if you do delete the TLG file QuickBooks will re-create it. Does it re-create the file with all of the old transactions or just the ones you have entered since the last time you deleted it?

    • Hi, Seth! Yes, QB will create a new TLG file if the existing one is deleted, but the new file will contain only transactions entered after it is recreated — the old stuff is gone for good. That’s why I recommend that it not be deleted, but if it must be deleted, save it off to a different location first.

  2. Rather than deleting your .TLG file, you can reduce its size by backing up your company file. I believe that the transaction log file is added back to the company file. I just tried it on my company file. I recommend to my clients in the Seattle area that I set up, review, and train in QuickBooks to do this on a weekly basis. Also, backing up verifies the data.

    • Keith, my understanding is that if you make a verified backup in QuickBooks, QuickBooks deletes the TLG file. I suppose the thinking is that if the verify is OK then there would be no need for the TLG. But that doesn’t account for the possibility of future problems, where sometimes it would be desirable to have a TLG that goes way back.

      If you make a backup without verifying, QB leaves the TLG file alone.

  3. I don’t think that when one makes a verified backup, QuickBooks deletes the TLG file. When I did my backup, QuickBooks didn’t delete my TLG file. It just got smaller.

    I always make a complete backup and advise my customers to do the same. That way if there is a problem in the company file, it will be detected during the backup process and the client can then fix it or rebuild their company file.

    I am wondering if the purpose of the TLG file is to store transactions between complete or verified backups. Which can then be used to repair a company file.

    • Keith, you are right — it doesn’t delete the TLG file. But it deletes the previous information in the file and leaves it essentially empty. Pretty much the same end result. The only use I know of for the TLG file is like you say: a way to recover from a data corruption episode.

      You might be interested in Charlie Russell’s analysis of this topic.

  4. Pingback: The QuickBooks Equivalent of Texting While Driving | QuickBooks and Your Business

  5. Pingback: The Case of the Exploding TLG File | QuickBooks and Your Business

    • Mark, that’s the tricky thing…you don’t need the TLG file when everything is working right. It’s potentially later, when verify/rebuild would fail, that having an uninterrupted TLG file can come in handy. Particularly if, for some reason, you don’t have a good current backup.

  6. My automatic backup service copies everything in specified folders so the .TLG file is also copied when I exit QB.
    I do not want to slow down the backup with this file as it can be larger than the .QBW file which may not be backed up by the time I need to turn off the PC to leave the office.
    I want to store the .TLG in an adjacent folder.
    How can I do this?

  7. River,

    There’s no way to configure QB to keep the TLG in a separate folder. If you are concerned about backing up such a large file, you could either “unflag” the TLG file to your backup software so that it is ignored, or you could create a “complete verified” backup within QuickBooks — that will reinitialize the TLG file and make it small so that it will be a quick backup.

    Hope that helps. Thanks for the question.

  8. Pingback: QuickBooks, If the Server Crashes « QuickBooks and Your Business

  9. I have a good back-up of my company file from June, I also have a back-up of my TLG file, how do I get the data from the TLG file to show in QB? If I copy both my company file and TLG to a folder it wont use the TLG file I put in and creates a new file. I know that all of my data from the last verified back-up is there, but I am getting frustrated and unsure how to retreave it. My accountant does not know how to get this to work either. Any assistance would be more than wonderful, as there is so much lost if I am unable to retrieve. thanks

    • Hi Joseph,

      It’s not something a user or accountant or regular QuickBooks Pro Advisor can do. We have tools that enable to us to do this process. I take it that there’s a problem with your current QBW file? Let us know if we can help, and thanks for the question.

  10. I have this issue with a client that when they do a manual backup it says that the file needs to be rebuilt. So I copied the file to a workstation and ran the rebuild which completed and then ran a manual backup again and it still says it needs to be rebuilt. Like it’s stuck in a loop. I tried with and without the old TLg file.

    I ran the intuit file Doctor which says that there is nothing wrong with the file.

    So I’m not sure how to proceed from here.

      • The thing is that we don’t know when the corruption happened. It can be a year ago or more. I ran the rebuild a few more times (which is not recommended I know) and then i tried to create a portable copy which it allowed me to do. After this I tried to create a full copy with normal verify which it passed and then full copy with complete verify which now also worked. The quickbooks version is Premiere 2014 and the file is almost 800 MB. I know its a big file and they are experiencing quickbooks running slow when typing and it hesitates. The file is on a Server 2012 on a gigabit network. I replaced the switch today because the server kept downgrading its connection to 100Mbit instead of 1Gbit.

        • Matt,

          So what I understand that you’re saying is that the file will verify but not rebuild. That happens sometimes.

          You might try running rebuild on the file several times…maybe as many as seven times. In some cases, it seems that rebuild makes incremental fixes to the file and you have to run it a lot.

          If that doesn’t work, probably getting your data repaired would be the most cost-effective approach to move forward.


Leave a reply

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong> 


This site uses Akismet to reduce spam. Learn how your comment data is processed.