When the application and agreement for the credit check service is filled out, it is for specific legal entity at a specific address. The location is then later inspected to verify its validity and requirements. Changing the name or address would break the credit check agreement. Hence the fields are locked.
How to Update:
Whether if it is to update the account's name or address, the application process for the credit check service will have to be resubmitted and the location inspected. Please review the below article for details.
There is also the option of removing the current credit check service, which will then allow the update of the account's name and address immediately.