How do you export files from QB UK Pro 2019 trial version to QB Online?

Hello,

  This works a bit different. You need to export files to a spreadsheet(s) from your QuickBooks Desktop and then with the use of stand-alone software import those spreadsheets to your QuickBooks Online. There are some apps - however I have used a Business Importer one that I liked most. 

It works in away that you just upload your exported files into the app, then do some basic mapping(and it can be even more easier if you will export stuff with the same app that you are importing) and then just click Import - and, woah, all your entities are starting to appear in your new QuickBooks Online company in a quick and responsive manner.

It's nice to have you here in the Community, jermaine-coelho.

Allow me to chime in this conversation to help export the QuickBooks Desktop file to QuickBooks Online (QBO).

To make sure you have the Export Company File to QuickBooks Online option, I recommend updating QuickBooks Desktop to the latest release. 

Let me show you how:

1. Select Help at the top menu bar, then choose Update QuickBooks.
2. Choose Update Now at the top, then check the box next to Reset Update.
3. Click Get Updates (see screenshot below).

Next, let's close QuickBooks Desktop by clicking File, then choosing Exit. Open QuickBooks again and finish installing the updates when prompted.

Now, you're ready to export the QuickBooks Desktop company data to QBO. Please follow the steps below:

1. Open the file you want to export.
2. Go to Company at the top menu bar.
3. Choose Export Company File to QuickBooks Online.
4. Follow the prompts to connect to QBO.

Lastly, connect to QBO and import your data. 

1. Enter your QuickBooks Online login, agree to the Terms of Service, and choose Sign in.
2. Select the QuickBooks Online company you want to import your data into, or create a new one.
3. Choose OK, got it.

Check out this article for the detailed steps: Convert QuickBooks Desktop file to QuickBooks Online.

These troubleshooting steps should get you back on track. I'd appreciate if you can update me on how it goes. I'll be here and ready to help anytime. Have a good one.