Could you let me know what country you're from? I can look into the requirements for your region to provide insight into what information we require to set up Shopify Payments for your account.
Thank you. I know that in the UK we will request either a business identification or registration number if you're not registering as a sole proprietor. The registration number is 8 digits long and typically starts with 0. Have you tried removing the 0 and using the other 7 digits?
This is an accepted solution.
If you are selecting the proper business type and the system is not recognizing your registration number, then we'll want to take a deeper look into the account.
While we’re not able to provide account-specific support via the Shopify Community at this time, we’d be happy to continue assisting you through live chat, email, or callback. Please visit https://bit.ly/3cJkx8V and log in to your account to create a support request.
Since this is the next step I've marked this reply as the solution for the benefit of others who may discover this topic. Thanks!