When you create a Company Code in SAP for a specific country (Ex. US), the Company Code will allow you enter certain additional parameters for that Company Code that are typical for a Country US to have them. (Ex. TIN - Tax Identification Number, and some other registration numbers that are typically required for companies doing business in the US).
For example, for Canada you will need to enter the GST Registration number, PST or QST numbers as well since your Company Code will be in country CA.
This is an important piece of information that is typically needed for Legal requirements in many countries to issue invoices showing your Registration number when you print an invoice or send information to the banks, Tax agencies or other regulatory entities. So this becomes a MUST HAVE to have it available in the system ready to be used by any of these processes.
But now, what happens if you have a US Company Code, that is registered in Canada and you need to enter the GST Number for it ?
In standard SAP configuration, you will not be able to do it within the Company Code Global settings (or Maintain Additional Parameters as of S/4 HAHA 1709), those fields for GST number will not be available since your Company is in country US and that is not required in the US.
How do you enter this in your US Company Code ?
There are 2 options
This configuration to allow you to enter this parameters is based on "Parameters Types" that are preconfigured for certain countries. In the case of GST Number, it is Parameter Type F29T01. You can look for your specific Parameter Type in Table T001I
Option # 1
SM30 on Table V_T001I
Remove country CA for this record "Parameter Type" = F29T01
If you do that, this will make type F29T01 available for any Company Code regardless of the Country. So all Company Codes all of a sudden will have available the GST Number to be entered even belonging to any country in the world. (For me this is not the preferred approach).
Option # 2
SM30 on Table V_T001S4H
Enter a new entry for F29T01 record and assign it to country US. If you look for F29T01, it is already assigned to Country CA as well.
This will allow to enter the GST Number for all US CoCodes. For me, this should be the preferred approach as it only affects Country US and not all countries.
Be aware that this could be overwritten by an SAP upgrade, so it might need to be redone later.
Once you are done with the configuration, you will be able to enter the foreign registration numbers in your Company Code within Company Code Global Parameters or Additional Parameters.