Plus there is the question of how big it is. If it is small (2 amps), then it is for lighting.
There are also medium (5amp) and large (15 amp) which are for different purposes. I.e. 5 amp would be ideal for a toaster, a tv or a larger light, and 15 for a washing machine, drier etc. You shouldn't wire on an over or underrated plug, the three sizes are for different loads. In someways its better than having fuses in plugs like we do now, as the fuse is at the CU , and it forces using the correct rating(how many times have you seen 13 amp sockets, attatched to a clock radio that have a 13 amp fuse in, simply out of lack of knowledge).
As long as it looks fairly modernish, it shouldn't need replacing.
Plus, you cannot replace such a socket with a thirteen ampere socket, they are on differently rated circuits.
If it does look old, what you might want to check is that the round pin sockets haven't just been replaced with 13 amp square pin sockets on the same circuit, which is unfortunately common practice by unexperienced DIYers.
2 amp
5 amp
15 amp
Images not to scale