Want to know if 1% is mandatory or law for the RE capital gain when selling property

I'm surprise about this since i m selling my 13 yr old h/l in suburb to my friend & i have been prompt with 1% from gain.

I forgot to clarify the 1%, will they base on cap gain assesed tax from BIR or gross value of property?

Do i have to pay the 1% or just optional? Or there maybe other ways like same old thing, u produce a deeds with the standard download form from internet then have it authorized & pay the P300...i remember it was like this..

Appreciate any inputs
Pls help me

I know it is against on your co-lawyers out there cos 1% is on your side but as a humann being i need appropriate & bias reply

For info this is quoted from Tax Reform Act of 1997 "(D) Capital Gains from Sale of Real Property. –

(1) In General. - The provisions of Section 39(B) notwithstanding, a final tax of six percent (6%) based on the gross selling price or current fair market value as determined in accordance with Section 6(E) of this Code, whichever is higher, is hereby imposed upon capital gains presumed to have been realized from the sale, exchange, or other disposition of real property located in the Philippines, classified as as capital assets, including pacto de retro sales and other forms of conditional sales, by individuals, including estates and trusts: Provided, That the tax liability, if any, on gains from sales or other dispositions of real property to the government or any of its political subdivisions or agencies or to government-owned or controlled corporations shall be determined either under Section 24 (A) or under this Subsection, at the option of the taxpayer."

When we sold the estate of our deceased parents, we paid 6% capital gains tax to BIR, the buyer paid 1.5% documentary stamp tax to BIR, and the notarial fee (2% of selling price indicated on the Deed of Sale) equally shared by seller (us) and the buyer. The tax paid to BIR was based on the selling price indicated on the Absolute Deed of Sale, or Fair Market Value indicated on the Tax Declaration or the Zonal Value commissioned by BIR, whichever is higher.

Note: I am an ordinary person sharing my opinions, ideas and experiences that maybe of help to you.