I have a peugeot 206 x reg and on my milage counter a spanner lights up. does any one what this means

it means its due for a service

This is letting you how many miles left until next service due, check handbook if you have recently bought the car and see when (if) last service was carried out

the light means that the car is due for a service

its due a service

Replace the timing belt

l would say it is due for a service l think if u take it to a peugeot dealer they reset it afterward l beleive