If this is a number in international format:
+44 represents United Kingdom
The following 70 indicates a personal 'follow-me' numbering or call diversion service.
Note that calls to +44 70 numbers may cost significantly more than calls to ordinary UK landline numbers (numbers beginning with +44 1 or +44 2).
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
The UK uses country code +44. Within the UK, area code 7748 (07748 domestically) is not a geographic area code, but instead identifies mobile numbers assigned to Vodafone. However, mobile numbers are portable, so a particular mobile number could be served by any mobile carrier.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
The "44" on those codes is the UK country code +44 for international calling. Within the UK, replace +44 with the trunk prefix 0.
070 (or +44 70) is the beginning of a personal "follow-me" number that can be forwarded to almost anywhere in the world.
074 through 079 (or +44 74 through +44 79) is the beginning of a UK mobile number.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
An international telephone number beginning with +44 70 is a UK-based personal "follow-me" number. You will be charged at the rate for calls to premium numbers in the UK (likely substantially higher than the cost of calling an ordinary UK landline number), but the person on the other end could be anywhere in the world. These numbers are quite popular with e-mail scammers, so be careful.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
All UK area codes begin with a 0. There is no area code 6010 in the UK, and there is no 06010 code either.
UK area code 020 is London.
There is no area code 20 in the UK
There is no 01134 code in the UK.
The country code and area code of Aberdeen, United Kingdom is 44, (0)1224.
Cambridge is in area code 01223, or +44 1223 from outside the UK.
In the UK, 0121 is the area code for Birmingham.
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.
The area code "029" is assigned to the city Cardiff in Wales, UK.
Slough. There is no 0753 code in the UK.
There is no UK area code like 0491. If the number is pre-1995 then this area code is now 01491 which covers Henley-on-Thames.
UK area code 0161 is Manchester. 0161 644 is an unused prefix.