Of course its not reliable, nor is the database the Police use either, lots of taxi drivers use weekly policies (for a variety of reasons), the police are forever stopping taxi drivers on such policies because their database is never up to date, impounding the car, at which point the driver has to pay something like 120 quid release fee (guilty of crime or not!), even if the driver has a policy document, the police still won't release the car until the database is showing the car as insured, (losing work in the process) and by the time the databse is updated, the insurance has run out again . You can see where this is going can't you