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.
01931 is the telephone code for Shap, Westmorland (near Penrith in Cumbria).
01691
UK telephone area code 0161 is Manchester, but 0161 553 is an invalid number block.
UK telephone area code 01954 (or +44 1954 in international format) is Madingley, Willingham, near Cambridge.
A UK telephone number beginning with +44 754 is a mobile.
01792 is the area code for Swansea
Until the early 1990's, area code +44 21 (or 021 within the UK) was Birmingham, which is now area code +44 121 (or 0121 within the UK). There has never been an area code +44 217 (or 0217) in the UK.
In the UK, area code 020 is London, but there are no numbers beginning with 020 2. Other countries may have similar telephone area codes.
UK telephone area codes were first assigned in 1958.
00 + 1 + Area code + telephone number.
UK area code 0141 is Glasgow, which has post codes beginning with G.
UK area code 020 is London, but there are no valid numbers beginning with 020 4, much less 020 43. Also, the area code for London is just 020, not 020x or 020xx. There are no other UK telephone area codes beginning with 020.