WITHHOLDING OF TAXES ON AIRLINES GOVERNMENT EMPLOYEES FOR OVERTIME SERVICES

one of my client is an international airlines (carrier of passenger). monthly we pay for the overtime services of different government agencies serving at the international airport, we have a problem with one of the agency cause they charge my client with overtime services plus meals plus transpo fixed amount for a number of personel. now we withheld 15% on the total amount but they only want to withheld on the overtimes services only, excluding the meals and transpo. i try to explain to them that the whole amount is subject to 15% tax cause it is a fixed amount per personnel its not reimbursement. they want a provision with the BIR regarding meals and transpo.can you help me site the ruling of BIR?

Under Revenue Regulations No. 2-98, as amended, Section 2.57.2(K) states that:
"(K) Additional income payments to government personnel from importer, shipping and airline companies, or their agents. - On gross additional payments by importers, shipping and airline companies, or their agents to government personnel for overtime services as authorized by law - Fifteen percent (15%)

For this purpose, the importers, shipping and airline companies or their agents, shall be the withholding agents of the Government;"

It can be gleaned from the said regulations that only overtime services are subject to the 15% withholding tax. The government agency is right on their contention that reimbursement for meals and transportation are not subject to withholding tax.