What is the basis in the valuation of property?

The value of the real property will be based on the selling price, fair market value as determined by the Commissioner (zonal value) or the fair market value as shown in the schedule of values of the Provincial or City Assessor, whichever is higher.

If there is no zonal value, the taxable base is whichever is higher of the gross selling price per sales documents or the fair market value that appears in the latest tax declaration.

If there is an improvement, the FMV per latest tax declaration at the time of the sale or disposition, duly certified by the City/Municipal Assessor shall be used. No adjustments shall be added on the said value, provided that the tax declaration bears the upgraded fair market value of the said property pursuant to Section 219 of R.A. No. 7160, otherwise known as the Local Government Code of 1991 and the last paragraph of the Local Assessment Regulations No. 1-92 dated October 6, 1992.

In case the tax declaration being presented was issued three (3) or more years prior to the date of sale or disposition of the real property, the seller/transferor shall be required to submit a certification from the City/Municipal Assessor whether or not the same is still the latest tax declaration covering the said real property. Otherwise, the taxpayer shall secure its latest tax declaration and shall submit a copy thereof duly certified by the said Assessor. (RAMO 1-2001)

For shares of stocks, it will be based on the net capital gains realized from the sale, barter, exchange or other disposition of shares of stocks in a domestic corporation, considered as capital assets not traded through the local stock exchange.

(Excerpts from Source : http://www.bir.gov.ph/taxinfo/tax_capgin.htm)