According to the Notice of the Ministry of Finance of State Taxation Administration of The People's Republic of China on Issues Related to Real Estate Tax and Urban Land Use Tax (Cai Shui [2009]128):

I. Property tax on the use of other units' real estate without rent

Taxable units and individuals who use other units' real estate without rent shall pay property tax according to the residual value of the real estate.

Therefore, even if the house use certificate contract is signed, the real estate tax should be calculated and paid by the actual user according to the original value of the house minus 10%-30% and the residual value according to 1.2%.

According to Article 2 of the Provisional Regulations on Urban Land Use Tax, units and individuals who use land in cities, counties, towns and industrial and mining areas are taxpayers of urban land use tax (hereinafter referred to as land use tax) and shall pay land use tax in accordance with the provisions of these regulations.

Therefore, as the actual user of taxable land, your company should pay the land use tax.

It is worth noting that the property tax paid according to the residual value of the house is much smaller than the property tax paid according to the rent.