Hi there, burngateengineer.

Thanks for joining the Intuit Community. Allow me to share some information about the message you encountered when filing the VAT return.

We received reports that some customers are getting an error when connecting to HRMC. Our engineers are diligently working towards finding a solution.

To make sure you'll get looped into any updates about the progress, I recommend you reach out to our QuickBooks Care Team. One of our specialists will gather your information in a secure environment and add you to the notification list.

You’ll receive an email once there’s an update about the issue. The most up to date contact information can be found here:

1. Go to Help at the top, then click on the Contact Us link.
2. In the How can we help? window, enter contact support in the field box.
3. Select Let’s talk.
4. Choose a way to connect with us.
5. Select Chat or Call us.

While waiting for the resolution, submit the tax return using this URL: /app/tax/mtd?stepId=validateStep. This way, you can submit the tax form. 

Once the permanent fix is made available, rest assured, I’ll let you know by updating this thread.

That should get you in the right direction.

I appreciate your patience while we look into this. If there’s anything else I can help you with, please know I’m just a comment away. Have a good one.