New client, old acct had desktop QB,they have sent me the back up, how do I upload this in QBO?

I can assist you with the process of transferring your QuickBooks Desktop backup file to QuickBooks Online, userstaceyswan2005. 

When exporting your company file to QuickBooks Online, it's important to remember that certain advanced features, such as advanced reporting and advanced inventory), start fresh so that all your data will move to QuickBooks Online. This ensures that all your data is appropriately transferred to QuickBooks Online. 

It's also important to note that some data may be missing due to product limitations on QuickBooks Online. This could include certain transactions, reports, or other data not supported by the platform. To minimize the risk of data loss, it's recommended to carefully review your existing company file before exporting it to QuickBooks Online. 

To migrate your file, here's how For QuickBooks Desktop Pro or Premier:

1. Sign in as an admin.
2. Go to Company, then select Export Your Company File to QuickBooks Online.
3. Tap Get started.
4. Sign in as an admin to your QuickBooks Online company.
5. Click Choose online company, and select the company you want to replace with your company file.
6. Press Continue.
7. If you track inventory in QuickBooks Desktop:
   • Select Yes to bring them over, then enter the as-of date.
     Note: Use the first day after your last tax filing period as your inventory start date.
   • Select No if you want to set up new items later in QuickBooks Online.
8. Enter Agree in the text field, then select Replace.
9. Select Yes, go ahead and replace the data, then select Replace.

You can find detailed instructions on moving your QuickBooks Desktop file to QuickBooks Online in this article: Move your QuickBooks Desktop file to QuickBooks Online.

In addition, here's an article to learn more about how QuickBooks handles your desktop data to online: Learn how features and data move from QuickBooks Desktop to QuickBooks Online.

I suggest you visit this page to learn what to expect after you migrate your data to QuickBooks Online: Learn about converting from QuickBooks Desktop to QuickBooks Online.

Note: Although these articles are written for the US region, the procedures are the same for the UK region.

If you require further assistance with managing your company data, please feel free to leave a comment below. I will get back to you as soon as possible. Take care.

@userstaceyswan2005 

Do you need to convert data from QB Desktop UK version to QB Online UK version, or else?