CT postcode district map, Canterbury
Supplier statuses last checked .
The CT postcode area covers 22 districts and 15,378 live postcodes, from CT1 to CT50. It is centred on Folkestone and also covers Margate, Dover, Canterbury, Fordwich and Ramsgate.
Districts here average 699 postcodes.
Where the CT districts sit
4 districts are plotted without a label where labels would overlap; every one is in the table below.
Where CT sits
The whole area sits inside Kent, which is unusual at this size.
Water supply across CT
All 22 CT districts are supplied by South East Water. That makes CT simple in a way many areas are not: one company, one set of rules, one status to check.
South East Water has a hosepipe ban in force from 3 July 2026, covering the whole of CT.
The shape of the CT area
The districts are wildly uneven: CT9 holds 1,216 postcodes around Margate and CT50 holds 5, a ratio of about 243 to one. They divide into 80 sectors.
The numbering is not continuous. CT runs up to 50 but has only 22 districts, so 28 numbers are unused:.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: CT18, CT19, CT20 and CT50 all point at Folkestone, CT7, CT8 and CT9 all point at Margate and CT15, CT16 and CT17 all point at Dover.
What borders CT
CT sits next to ME (Rochester) to the west, TN (Royal Tunbridge Wells) to the west, SS (Southend-on-Sea) to the north west, DA (Dartford) to the west and RM (Chigwell) to the north west.
CT districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| CT1 | Canterbury | South East Water / Southern Water | Depends on your supplier |
| CT2 | Fordwich | South East Water / Southern Water | Depends on your supplier |
| CT3 | Fordwich | South East Water / Southern Water | Depends on your supplier |
| CT4 | Canterbury | South East Water / Southern Water | Depends on your supplier |
| CT5 | Whitstable | South East Water / Southern Water | Depends on your supplier |
| CT6 | Herne Bay | South East Water / Southern Water | Depends on your supplier |
| CT7 | Margate | South East Water / Southern Water | Depends on your supplier |
| CT8 | Margate | South East Water / Southern Water | Depends on your supplier |
| CT9 | Margate | South East Water / Southern Water | Depends on your supplier |
| CT10 | Broadstairs | South East Water / Southern Water | Depends on your supplier |
| CT11 | Ramsgate | South East Water / Southern Water | Depends on your supplier |
| CT12 | Ramsgate | South East Water / Southern Water | Depends on your supplier |
| CT13 | Sandwich | South East Water / Southern Water | Depends on your supplier |
| CT14 | Deal | South East Water / Southern Water | Depends on your supplier |
| CT15 | Dover | South East Water / Southern Water | Depends on your supplier |
| CT16 | Dover | South East Water / Southern Water | Depends on your supplier |
| CT17 | Dover | South East Water / Southern Water | Depends on your supplier |
| CT18 | Folkestone | South East Water / Southern Water | Depends on your supplier |
| CT19 | Folkestone | South East Water / Southern Water | Depends on your supplier |
| CT20 | Folkestone | South East Water / Southern Water | Depends on your supplier |
| CT21 | Hythe | South East Water / Southern Water | Depends on your supplier |
| CT50 | Folkestone | South East Water / Southern Water | Depends on your supplier |
Principal settlement is the town or city each district sits in or nearest to, derived from OS Open Names. It is not the Royal Mail post town, which is licensed data and not published openly. Status is resolved live from each company’s own notice.
Water hardness in CT
No water company covering CT publishes hardness figures as open data. The gap is named per district below so you know who to ask.
| District | Hardness | As published | Supply zone | Published by |
|---|---|---|---|---|
| CT1 | Not published by South East Water. Check with your supplier. | |||
| CT2 | Not published by South East Water. Check with your supplier. | |||
| CT3 | Not published by South East Water. Check with your supplier. | |||
| CT4 | Not published by South East Water. Check with your supplier. | |||
| CT5 | Not published by South East Water. Check with your supplier. | |||
| CT6 | Not published by South East Water. Check with your supplier. | |||
| CT7 | Not published by South East Water. Check with your supplier. | |||
| CT8 | Not published by South East Water. Check with your supplier. | |||
| CT9 | Not published by South East Water. Check with your supplier. | |||
| CT10 | Not published by South East Water. Check with your supplier. | |||
| CT11 | Not published by South East Water. Check with your supplier. | |||
| CT12 | Not published by South East Water. Check with your supplier. | |||
| CT13 | Not published by South East Water. Check with your supplier. | |||
| CT14 | Not published by South East Water. Check with your supplier. | |||
| CT15 | Not published by South East Water. Check with your supplier. | |||
| CT16 | Not published by South East Water. Check with your supplier. | |||
| CT17 | Not published by South East Water. Check with your supplier. | |||
| CT18 | Not published by South East Water. Check with your supplier. | |||
| CT19 | Not published by South East Water. Check with your supplier. | |||
| CT20 | Not published by South East Water. Check with your supplier. | |||
| CT21 | Not published by South East Water. Check with your supplier. | |||
| CT50 | Not published by South East Water. Check with your supplier. | |||
Hardness is published per census area, not per postcode, so these figures characterise a district rather than measuring one address. They are a scale and taste matter, not a safety one. Hardness data version wessex-water@2022-2025+yorkshire-water@2026.
Download the CT data
No signup, no email wall. GeoJSON carries the district points, the supplier and the live status, so it can be dropped straight into a map.
District positions are averaged postcode centroids from OS Code-Point Open. They show roughly where a district sits, not where its boundary runs, and are not legal boundaries.
Frequently asked questions
How many postcode districts are in the CT area?
There are 22 CT postcode districts, running from CT1 to CT50, and they contain 15,378 live postcodes across 80 sectors.
What towns does the CT postcode area cover?
CT covers Folkestone, Margate, Dover, Canterbury, Fordwich and Ramsgate. The area takes its name from Folkestone, and each district is listed with its settlement in the table on this page.
Which water company supplies CT postcodes?
South East Water supplies all 22 CT districts. Supply boundaries follow the pipe network rather than postcode geography, so confirm against your water bill if you are near the edge of the area.
Why do CT18 and CT19 both say Folkestone?
CT18, CT19, CT20 and CT50 all serve Folkestone, covering different parts of it. A single town routinely needs more than one postcode district once it passes a few thousand delivery points, so this is normal rather than an error in an address.
Can I download a free CT postcode map?
Yes. This page offers the CT districts as GeoJSON, CSV and SVG, free and with no signup or email address required. The GeoJSON carries each district's position, its water company and its current restriction status, so it can be dropped straight into a mapping tool.
Why is the CT area called Canterbury when it covers Margate?
CT takes its letters from Canterbury, where the sorting office that served the area was based when the code was allocated. Margate is the largest settlement in the area today, in CT9, but the area code follows the historic sorting geography rather than current population.
Why is there no CT49 postcode district?
CT49 is not in use. Postcode districts are allocated as sorting requirements change rather than numbered straight through, and a code that is retired or never brought into service is not reissued, so gaps in the sequence are normal.