A magnetic recording medium is made by applying a coating mixture having magnetic particles dispersed in a binder and drying the coating mixture so as to produce a coding layer containing tamper-proof identifier coding information comprising designed patterns, letters, numerals and bar-code type patterns. Another magnetic layer for recording regular magnetic data can be provided above or below the coding layer. The coding information can neither be read or altered by ordinary magnetic reader. The magnetic recording medium is therefore useful for such applications as shopping cards, pre-paid cards, retail store cards; financial cards including credit cards, insurance cards; travelling cards including transit passes, tickets; and identification cards including passports, birth certificates and other personal identification cards. A method of making such a magnetic recording medium is also presented in which the coating mixture is applied on a non-magnetic base material, and while the coating mixture is still wet, i.e. while the magnetic particles are mobile, suitable coding information is magnetically recorded. The coating mixture is then dried to fixate the identifier coding information in the coding layer to produce fixated coding information which is non-erasable and non-alterable.