Tax Identification Number is a Requirement for One-Time Transactions

The Bureau of Inter Revenue (BIR) recently issued Revenue Memorandum Circular No. 90-2017 which formally requires the donee(s) in donor’s tax transactions, heir(s) in estate tax transactions, and buyer(s) in sales of shares of stock to obtain a Tax Identification Number (TIN) prior to their application for an Electronic Certificate Authorizing Registration (eCAR). The TIN requirement is a mandatory field in the eCAR System.
Thus, taxpayers may no longer contest the BIR in requiring a TIN for these transactions for the reason that the same is not listed as a requirement. 
The full text of Revenue Memorandum Circular No. 90-2017 is available here.