Buyer identification for government entities

Our client is a government entity in KSA. What buyer identification shall be used for Tax Invoices?

In case of Government customers, if they do not have VAT Registration Number(BT-48) then the field Other Buyer ID (BT-46) becomes mandatory. You should try to get any of the listed IDs from BR-KSA-14. If none of listed IDs is available, you can provide any available ID on category “OTH” (others). The invoice will not be rejected even if both fields are left blank (BT-48 and BT-46). Such invoices will be “accepted with warnings” and you can explain the reason if ZATCA teams request for explanation in future that IDs were not available despite reasonable effort with supporting evidence.