The cars MOT retest period begins next week, what happens if i get it tested and it fails? has the validity of the old MOT run out the moment the new test occurs, or is the old test valid until its expiry date.

I don't think the car will fail just want to know what the worst case scenario is? living and working 150miles apart would make being without a car for even a few days a problem.

Old test valid until original expiry date…

If it fails, once the work is done take it back to the same garage who are obliged to retest it for free…