In the System, Company screen, the company details that are entered here at used by Dimensions to generate the file that gets sent across to HMRC.
HMRC requires the information in this Company screen to match the details that they have on record.
You can log into the Government Gateway and retrieve the information from there if required.
This includes:
Company Name
Branch ID
Address
Postcode
VAT Registration Number
Company Registration Number
As long as these all match the information that HMRC have, the submission will be successful.