London postal district (English Wikipedia)

"Walthamstow: Transport and postal services" Archived 25 May 2011 at the Wayback Machine, A History of the County of Essex: Volume 6 (1973), pp. 250-251. Retrieved 14 December 2007.
"Wanstead: Introduction" Archived 25 May 2011 at the Wayback Machine, A History of the County of Essex: Volume 6 (1973), pp. 317-322. Retrieved 22 December 2007.
"Little Ilford" Archived 25 May 2011 at the Wayback Machine, A History of the County of Essex: Volume 6 (1973), pp. 163-174. Retrieved 14 December 2007.

competition-commission.org.uk

Map of London district names and numbers, from the 1963 edition of Bartholomew's Reference Atlas of Greater London

Honeypot Close in the London Borough of Harrow is within NW9 postcode, the only address in the Borough which is inside the London Postal District; see: "Map of Honeypot Close, London, NW9". Archived from the original on 30 July 2012. Retrieved 11 January 2010. and "Harrow Council". Archived from the original on 16 June 2011. Retrieved 11 January 2010.

"Area and Property Guide for n11 - Mouseprice". www.mouseprice.com. Archived from the original on 21 March 2018. Retrieved 20 March 2018.

Honeypot Close in the London Borough of Harrow is within NW9 postcode, the only address in the Borough which is inside the London Postal District; see: "Map of Honeypot Close, London, NW9". Archived from the original on 30 July 2012. Retrieved 11 January 2010. and "Harrow Council". Archived from the original on 16 June 2011. Retrieved 11 January 2010.

"Cracking the code's not easy" Archived 26 May 2008 at the Wayback Machine. This is Local London, 12 March 2002.

IGWE managed the project.Archived 30 September 2007 at the Wayback Machine - John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72)

IGWE managed the project.Archived 30 September 2007 at the Wayback Machine - John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72)
"Walthamstow: Transport and postal services" Archived 25 May 2011 at the Wayback Machine, A History of the County of Essex: Volume 6 (1973), pp. 250-251. Retrieved 14 December 2007.
"Wanstead: Introduction" Archived 25 May 2011 at the Wayback Machine, A History of the County of Essex: Volume 6 (1973), pp. 317-322. Retrieved 22 December 2007.
"Little Ilford" Archived 25 May 2011 at the Wayback Machine, A History of the County of Essex: Volume 6 (1973), pp. 163-174. Retrieved 14 December 2007.
"Cracking the code's not easy" Archived 26 May 2008 at the Wayback Machine. This is Local London, 12 March 2002.
Honeypot Close in the London Borough of Harrow is within NW9 postcode, the only address in the Borough which is inside the London Postal District; see: "Map of Honeypot Close, London, NW9". Archived from the original on 30 July 2012. Retrieved 11 January 2010. and "Harrow Council". Archived from the original on 16 June 2011. Retrieved 11 January 2010.
Calder, S., "London's in-crowd". The Independent (London), 26 October 1996.
"Area and Property Guide for n11 - Mouseprice". www.mouseprice.com. Archived from the original on 21 March 2018. Retrieved 20 March 2018.
"Names of Streets and Places in the London Postal area". HMSO. 1930. Archived from the original on 20 October 2004. Retrieved 22 January 2012.