I had to get a new V5c when the selling dealer input my first name in its diminutive form (similar to Bob/Robert). I am not sure it would have been a problem to have left it but DVLA changed it and did not add to the owners figure.

They've changed the design/security watermarks a couple of times and reissued them in bulk.

Other Possible Reasons:

Duplicate as original lost.

If there were a change to the vehicle such as colour or engine number.

Change of Keeper's address or name- remember the name on the V5 is that of the Keeper. They may not own the vehicle.

There may be others.

It might help to know why you're asking.

Including correcting any mistakes from when it was originally issued. My car's V5 incorrectly stated it was 'grey' instead of 'silver' - until I saw my dad's car's V5 (his car is also silver), I wrongly assumed that the DVLA had set up a simple system with limited colours.

I contacted the DVLA, who advised me to use the V5 to correct the mistake or change details due to (as you say) resprays, etc, and they just sent me a replacement with the corrected data.