No. The uniform and clothing allowance of government employees is not taxable.
The uniform and clothing allowance of government employees amounting to P6,000.00 per year is among the authorized de minimis benefits under Revenue Memorandum Circular No. 50-2018 which is exempt from taxation.
Note however that while the uniform or clothing allowance of government employees is already ₱7,000.00 per year starting 2024, only the ₱6,000.00 is exempt from withholding tax, per the aforementioned Revenue Memorandum.
Unless the subject Revenue Memorandum is amended, such that the whole amount of ₱7,000.00 is exempt from withholding tax, then the ₱7,000 uniform or clothing allowance is not taxable. Otherwise, the ₱1,000.00 of it is subject to tax.