Downham is a village in Essex, England.
It is situated within the CM11 postcode district, which is within the Billericay post town.
The full list of postcode districts within the Billericay post town is as follows:
The Billericay post town is within the Chelmsford postcode area.
Administrative Ward: South Hanningfield, Stock and Margaretting
Administrative District: Chelmsford
Administrative County: Essex
Country: England
UK Parliament: Maldon
NHS Local Health Authority: East of England
NHS Region: North, Midlands and the East