town or city. At the time of the change, the subscriber part of the number gained an extra digit in London, those in Northern Ireland gained two or three digits, and the subscriber part of the number in the other areas gained two digits. All of these areas were also subject to a previous code change, one that added a "1" directly after the initial zero as a part of PhONEday in 1995. Five-digit area codes Five-digit area codes have either five-digit subscriber numbers or a mix of four- and five-digit subscriber numbers. Five-digit area codes always share their first four digits with four-digit area codes. (01xx xx) xx xxx and (01xx xx) xxxx This is the oldest geographic number format and is used for twelve smaller towns and villages where the subscriber number is either five or (in one area code) four digits long. These are known as 5+5 and 5+4 format. Therefore, the STD code and the subscriber number does not always total ten digits after the initial zero trunk code. These area codes were changed by adding a "1" directly after the initial zero as a part of PhONEday in 1995. The number of places using these two formats has declined rapidly in recent decades and Brampton is the last place in the UK with four-digit local numbers. The above twelve area codes and their six 'parent' area codes (01387, 01524, 01539, 01697, 01768 and 01946) are known as 'Mixed' areas due to multiple area codes sharing the same SABC digits (i.e. the initial zero and the following four digits). National dialling only ranges These ranges have subscriber numbers beginning with the digits "0" or "1", e.g.: Currently, these numbers are mostly used as the termination points for non-geographic numbers, and by some automated systems such as alarms. As such they are not usually meant to be directly dialled. Using these numbers directly has been problematic as some mobile phone operators in the UK do not allow access to these ranges, and there may also be difficulty accessing these numbers from outside the UK. Regulator Ofcom proposes that in future these ranges be released for wider, general-purpose use in up to 70 area codes facing number shortage but then, in order to avoid confusion with codes beginning with these digits, the area code would always have to be dialled for all calls, even from within the same