Is a postcode flood check the same as a property survey?

No. A postcode check is area based and indicative: it tells you about the area around a postcode centroid, not about your building, its floor level or its defences. It is a good first question and never the last word.

What do the flood risk bands mean?

The Environment Agency's rivers and sea bands run from very low to high, describing the chance of flooding in any given year for that area. High means greater than a 3.3% chance a year; very low means below 0.1%.

How to check the flood risk for your postcode

Q: How do I check the flood risk for my postcode in the UK?

For an England postcode you can get an indicative rivers and sea risk band in seconds from Environment Agency open data. Wales, Scotland and Northern Ireland each keep their own flood map, because the Environment Agency dataset covers England only and its silence about another nation is not a low score.

You can get an indicative answer in about ten seconds, free, without giving anybody your name. Here is how, and what the answer does and does not tell you.

How do I check the flood risk for my postcode in the UK?

Tradelynx's free flood check returns an indicative rivers and sea band for an England postcode from Environment Agency open data, no account needed. That dataset covers England only, so Welsh, Scottish and Northern Irish postcodes are sent to their own nation's map rather than a reassuring silence. It is area-based, excludes surface water, and the official checker still counts.

By Mike Fellows, Founder, Tradelynx · IT and service management backgroundPublished 16 September 2026Last reviewed 16 September 2026

The quick check

Our flood check takes a postcode and returns the rivers and sea risk band for that area, from the Environment Agency’s open Risk of Flooding from Rivers and Sea dataset. No account, no email address. We pass the postcode and nothing else.

Which nation your postcode is in changes the answer

This is the part most tools get wrong, and it matters more than the band does. The Environment Agency’s dataset covers England. Ask it about a Cardiff or Glasgow postcode and it has nothing to say, and a tool that renders that silence as "very low" has given you a reassuring answer rather than an answer.

England: the Environment Agency long term flood risk service.
Wales: Natural Resources Wales flood risk map.
Scotland: SEPA flood maps.
Northern Ireland: the Department for Infrastructure flood maps.

We check which nation a postcode is in first and send you to the right map rather than answering from the wrong dataset.

What the bands mean

They describe the chance of flooding in any given year for the area: high is greater than 3.3%, medium between 1% and 3.3%, low between 0.1% and 1%, and very low below 0.1%.

What a postcode check is not

It is area based and indicative, taken from a postcode centroid. It knows nothing about your floor level, your defences, or which side of the street you are on. It covers rivers and the sea, and not surface water, which is what actually floods a great many homes. For anything that turns on the answer, a mortgage, an insurance quote, a purchase, the official checker for your nation is the one that counts.

Contains Environment Agency information © Environment Agency and database right. Postcode location data from Ordnance Survey and ONS under the Open Government Licence.

If the answer matters to you beyond curiosity, it is worth keeping. A HomeLynx Passport holds this alongside the rest of what is known about your home, free, for any UK address.