Blue badge holders can park for free in pay-and-display and parking meter spaces with no time restrictions. If you have a blue badge you can park on single and double yellow lines for up to 3 hours as long as there isn't a loading ban and you aren't creating an obstruction.
In Kensington and Chelsea, Westminster, City of London and some areas of Camden there are more restrictions on where blue badge holders can park. In these areas different badges can be allocated for residents which allow them to park in more places than someone with just a blue badge. See below for details on how to contact your local council for more information.
The Blue Badge Parking website displays disabled parking spaces available on public roads in UK.