A few of my friends over the last couple of years have been hit with a bill from a local goverment office, in some cases the

tax seemed to be on the house and land,while on others just on the land. It seems the amount is approx 12.5 percent.

Any ideas what tax this will be?

Building and Land Tax, 12.5% on commercial (leased) property. Local Land Tax, a few baht per rai per year.

So they are counting a lease from a Thai wife to her Farang husband as a commercial leased property, that way they can collect 12.5%,

is this what you are saying ?, and if so when did this tax come into being ? I ask this 2nd question because I never paid this tax when I bought my land more than 10yrs ago, it was not my wife who I made the lease agreement with but a friends wife.

The 12.5% Building and Land Tax is the responsibility of the landowner or lessor.

Also one of the reasons 3 year contracts or shorter are popular with Thai owners.

They stay of the radar that way.

When you own land and house and lease it out, then that is 'commercial'.