Birmingham, UK doesn't have just one postal code ! Each UK postal code only applies to a small number of properties - typically up to ten buildings ! You would need to provide much more information to get a more accurate answer.
Assuming you meant 'Birmingham' - there are literally hundreds of postal codes for the Birmingham area. Each code only applies to a small number of properties. You would need to be more specific.
UK postal codes beginning with WR are in and around Worcester. A UK postal code beginning with WR10 is in Pershore, Worcestershire.
In the UK, 0121 is the area code for Birmingham.
The UK does not have one postal code for the entire country.
UK Postal codes start differently depending on which area you are posting to.
It a code for your yahoo.
W1a 1aa
Yes, all addresses in the UK have a postal code.
No
The UK does not use zip codes it uses postal codes. Warwickshire has many different postal codes
All Glasgow postcodes begin G.
L37 2DX