WD18 postcode district: Watford and around, Hertfordshire

WD18 is a postcode district in Hertfordshire, with 714 postcodes in use in 6 sectors. It has postcodes in Watford and Rickmansworth. It is split between 2 councils: Watford (655 postcodes) and Three Rivers (59).

Postcodes in use: 714
Sectors: 6
Councils: 2 councils
Places: 2 places

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026. See all our data sources

Every postcode in WD18, and which are new since 2020

New since 2020: 89
In use before 2020: 625
Outline: where 5 or more new postcodes since 2020 lie together

Of the 714 postcodes in WD18 that ONS places, 89 are new since 2020 and 625 were in use before 2020.

Each mark is a postcode's centre point as ONS gives it, not a building. Press one to see its postcode and open its page. New since 2020 means it came into use in January 2020 or later. A dashed outline shows where 5 or more lie within 150 metres of each other. It is not a boundary, and no boundary is drawn. Where marks overlap, the one first in the key is drawn; the counts include every postcode.

The middle of its postcodes: latitude 51.6491, longitude -0.4146. Open this area on OpenStreetMap

Source: Office for National Statistics (ONS) Postcode Directory, August 2026, loaded 20 October 2026, the centre point of each postcode; when each came into use: the same directory; roads, rivers and built-up areas: Contains OS data © Crown copyright and database right 2026. Drawn by us. Street map: Ordnance Survey, OS Open Zoomstack, Open Government Licence v3.0, drawn with MapLibre. How we use them

The 5 newest postcodes

WD18 1RLJuly 2026 WD18 1RNJuly 2026 WD18 7FAJuly 2026 WD18 1RJJune 2026 WD18 1RFMay 2026

Where the new postcodes lie together

42 new postcodes since 2020, outlined on the map. WD18 1RL, is the newest of them.
13 new postcodes since 2020, outlined on the map. WD18 7FA, is the newest of them.
7 new postcodes since 2020, outlined on the map. WD18 8AU, is the newest of them.
6 new postcodes since 2020, outlined on the map. WD18 0LZ, is the newest of them.
5 new postcodes since 2020, outlined on the map. WD18 8JB, is the newest of them.

What broadband can you get in WD18?

Ofcom reports on 595 of the 714 postcodes in WD18. At 528 of them every home and business can get gigabit broadband.

Postcodes where every home can get gigabit528 of 595

Postcodes where every home can get superfast580 of 595

Ofcom gives each postcode's share of homes and businesses, not how many there are, so these count postcodes. Each postcode page has its own figures. A provider's checker answers for one address.

Check one address on Ofcom's checker

Source: Ofcom, Connected Nations, Spring 2026, data for January 2026, Open Government Licence v3.0. How we use it

Is WD18 at risk of flooding?

17 of the 714 postcodes in WD18 have a home or business in an area at risk of flooding from rivers or the sea, the Environment Agency says. At those, it puts 82 homes and businesses in an area at high or medium risk.

Homes and businesses in an area at risk, at 17 of 714 postcodes High: 67Medium: 15Low: 201

High: 3.3% or more a year (1 in 30). Medium: 1% to 3.3% a year. Low: 0.1% to 1% a year. Very low: under 0.1% a year (1 in 1,000). Each band is the chance of flooding in any one year.

Homes and businesses in an area at risk of flooding from rivers or the sea, as the Environment Agency counts them, added up over the postcodes. It is for the land, not each building, and leaves out surface water, groundwater and sewers. Each postcode page has its own figures and its flood warning areas.

Source: Environment Agency, Risk of Flooding from Rivers and Sea (postcodes in areas at risk), published 6 July 2026, Open Government Licence v3.0. How we use it

What do homes sell for in WD18?

Homes in WD18 sold for a typical £370,000 in the 12 months to August 2026, across 188 sales, down 7.5% on the 12 months before, HM Land Registry's figures show.

£370,000 typical price, the 12 months to August 2026

£400,000 12 months to August 2025

▼ down 7.5% on the 12 months before

Detached £901,000 5 sales
Semi-detached £522,500 18 sales
Terraced £415,000 65 sales
Flat or maisonette £283,750 100 sales

Each bar is that kind's typical price, against the most expensive kind here.

Standard sales of homes at market value. A typical price is the median, the middle sale. Sales take weeks to be registered, so the last month or two are incomplete. Each postcode page gives the figure for its own postcode sector.

Source: HM Land Registry Price Paid Data, files dated 28 September 2026. Contains HM Land Registry data © Crown copyright and database right 2021. This data is licensed under the Open Government Licence v3.0. How we use it