An apparatus (30) for determining a coincidence of a position with a reference position, wherein radio signals from fixedly positioned radio transmitters can be received at the position, having means (32) for providing properties (MP(i)) of the radio signals of the fixedly positioned radio transmitters at the position, wherein the provided properties of the radio signals include transmitter identifications identifying the radio transmitters, means (34) for separating the radio transmitters into a first number (Neq) of radio transmitters previously recorded transmitter identifications of which at the reference position are identical with transmitter identifications provided at the position, and into a second number (Nneq) of radio transmitters previously recorded transmitter identifications of which at the reference position and transmitter identifications provided at the position are different, and means (39) for determining a measure of matching for the position on the basis of the provided properties (MP(i)) of the radio signals, wherein both properties (36) of the first number (Neq) of radio transmitters and properties (37; 38) of the second number (Nneq) of radio transmitters are taken into account in the determination of a measure of matching, and wherein the properties of the first number of radio transmitters and the properties of the second number of radio transmitters enter the measure of matching differently.