DN21 postcode district: Gainsborough and around

DN21 is a postcode district mostly in Lincolnshire, with 1,371 postcodes in use in 6 sectors. It has postcodes in Gainsborough, Kirton in Lindsey and Scotter. It is split between 3 councils: West Lindsey (1,215 postcodes), North Lincolnshire (152) and Bassetlaw (4). 1,215 are in Lincolnshire and 4 in Nottinghamshire. ONS lists no county for the other 152.

Postcodes in use: 1,371
Sectors: 6
Councils: 3 councils
Places: 3 places

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

Every postcode in DN21, and which are new since 2020

New since 2020: 81
In use before 2020: 1,290
Outline: where 5 or more new postcodes since 2020 lie together

Of the 1,371 postcodes in DN21 that ONS places, 81 are new since 2020 and 1,290 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 170 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 53.4192, longitude -0.7037. 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

DN21 1WZMarch 2026 DN21 4FJMarch 2026 DN21 1AZFebruary 2026 DN21 1WWFebruary 2026 DN21 1NPDecember 2025

Where the new postcodes lie together

9 new postcodes since 2020, outlined on the map. DN21 1NP, is the newest of them.
6 new postcodes since 2020, outlined on the map. DN21 1FP, is the newest of them.
6 new postcodes since 2020, outlined on the map. DN21 1WW, is the newest of them.
6 new postcodes since 2020, outlined on the map. DN21 9FJ, is the newest of them.

What broadband can you get in DN21?

Ofcom reports on 1,335 of the 1,371 postcodes in DN21. At 802 of them every home and business can get gigabit broadband, and at 20 some cannot get decent broadband (10 Mbit/s).

Postcodes where every home can get gigabit802 of 1,335

Postcodes where every home can get superfast1,043 of 1,335

Postcodes where some cannot get decent broadband20 of 1,335

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 DN21 at risk of flooding?

328 of the 1,371 postcodes in DN21 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 1,688 homes and businesses in an area at high or medium risk.

Homes and businesses in an area at risk, at 328 of 1,371 postcodes High: 101Medium: 1,587Low: 2,313Very low: 1,067

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 DN21?

Homes in DN21 sold for a typical £177,500 in the 12 months to August 2026, across 486 sales, up 1.4% on the 12 months before, HM Land Registry's figures show.

£177,500 typical price, the 12 months to August 2026

£175,000 12 months to August 2025

▲ up 1.4% on the 12 months before

Detached £279,000 188 sales
Semi-detached £170,000 136 sales
Terraced £110,000 147 sales
Flat or maisonette £80,000 15 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