Where in the UK is telephone area code 01912?

UK telephone area code 0191 is Tyneside, Sunderland, and Durham, sometimes collectively referred to as Tyne & Wear. The first digit of the local number specifies in which area the number is located. A number beginning 0191 2 is in the North Tyneside/Newcastle area, but the '2' is the first digit of the local number, not part of the area code.