Some jurisdictions do not issue a TIN. If so, the customer must state so. However, most countries issue TIN and if that is the case, the customer must provide its TIN. Please note that the customer in certain situations may not have a TIN and must in such cases apply for a TIN according to local regulations.
Further details on jurisdiction specific TIN formats can be found at: http://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/#d.en.347759