Hi Alex,

It depends on which engine your car has. 

The belt on the 1.6 TDI engine is good for 210,000km regardless of time for example.

On the petrol engines, the belts are supposed to be "long life", which means no need to even check them for 300,000km or 15 years, but I must admit I've never been very confident in that myself. I'd suggest contacting a SEAT dealer with your full car details and asking them about it. If they confirm what we said, then perhaps pay your garage to remove the top cover of the belt to inspect it instead. This is a relatively small job to reassure you the belt is in good condition. Incidentally, regular maintenance of the engine and servicing is unlikely to have any bearing on this. If they say the belt should be changed then we are not in a position to argue with an official representative of the company.

Of course, if you want to change the belt for added reassurance, there's no reason not to - aside from cost.