Are London Postcodes Alphabetical?

Mystery Hour Question 

How do London postcodes operate? Why is  South East 1 (SE1) not next to South East 2 (SE2). What is the link with the postcodes? They’re not next to each other.

Bev, Camberwell 

Answer

**Definitive-ish**

Name: David, Hackney

Qualification: Lorry Driver

Answer: Postcodes in London are alphabetical. An area starting with A will be denoted a 1, with the next alphabetical area given 2.  For example:
SE2: Abbey Wood district: Abbey Wood, West Heath, Crossness, Thamesmead (part)     Bexley, Greenwich
SE3: Blackheath
SE4: Brockley