Polyester film for recording medium and magnetic recording tape

A polyester film for recording medium, having one major surface thereof provided with a coating layer containing fine particles with a particle diameter of 5 to 50 nm and an organic compound, wherein a number of fine surface projections existing on a surface of said coating layer is in a range of 3 million to 7 million/mm2, and a number of surface defects with a height of 120 nm or greater attributed to foreign matter attributed to a catalyst, contained in said film is 15/100 cm2 to 30/100 cm2, and wherein a polyester of said polyester film contains 1) a titanium compound at a content of 2 to 6 ppm as a titanium atom equivalent relative to polyester and a phosphorus compound at a content of 0.2 to 9 ppm as a phosphorus atom equivalent relative to polyester, and a ratio of a content of said titanium compound to a content of said phosphorus compound is in a range of 0.7 to 10 at a molar ratio (Ti/P) of titanium atom to phosphorus atom, and not having a particle shape of titanium dioxide, and 2) 0 ppm of antimony and 0 ppm of germanium.