code number of UK
00 1 then the area code and then the number
This is the start of a UK mobile (cell) phone number.
Country code +44 is the UK, and +44 3 is an all-UK number.
To dial a UK mobile, you always dial the UK mobile number, no matter where the mobile is physically located.
If the Dubai mobile has international roaming, it can be called by dialing the UAE number, country code +971. If you want to reach that phone by dialing a UK number, you may be able to swap in a UK SIM card.
The code for the UK from any country is 44
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.
A UK telephone number beginning with +44 754 is a mobile.
Because it's a mobile number, it can be anywhere in the UK.
00 + 1 + Area code + telephone number.
UK telephone area code 0161 is Manchester, but 0161 553 is an invalid number block.