CF postcode district map, Cardiff
Supplier statuses last checked .
We’re re-checking Welsh Water. Its last confirmed status is still shown here, because hiding a restriction we cannot currently re-read is the more expensive mistake, last confirmed 29 days ago.
The CF postcode area covers 39 districts and 23,435 live postcodes, from CF3 to CF99. It is centred on Cardiff and also covers Caerphilly, Merthyr Tydfil, Barri, Aberdare and Pen-y-bont ar Ogwr.
Districts here average 601 postcodes.
Where the CF districts sit
11 districts are plotted without a label where labels would overlap; every one is in the table below.
Where CF sits
It is administratively fragmented, reaching into Cardiff, the Vale of Glamorgan, Rhondda Cynon Taf and Bridgend and 4 other authorities.
Every CF postcode is in Wales. Water there is regulated by Natural Resources Wales rather than the Environment Agency.
Water supply across CF
All 39 CF districts are supplied by Welsh Water, which is notable at this size: an area with this many districts usually crosses at least one supply boundary, and this one does not.
No hosepipe ban currently applies anywhere in CF.
The shape of the CF area
The districts are wildly uneven: CF14 holds 1,662 postcodes around Cardiff and CF99 holds 1, a ratio of about 1662 to one. They divide into 154 sectors.
The numbering is not continuous. CF runs up to 99 but has only 39 districts, so 58 numbers are unused:.
Several districts share a settlement, which is a common source of confusion when a form rejects an address: CF3, CF5, CF10, CF11, CF14, CF23, CF24, CF30, CF91, CF95 and CF99 all point at Cardiff, CF15 and CF83 all point at Caerphilly and CF33 and CF36 all point at Porthcawl.
What borders CF
CF sits next to NP (Pontypool) to the north east, BS (Bristol) to the east, TA (Taunton) to the south, LD (Llandrindod Wells) to the north and HR (Hereford) to the north east.
Its neighbours run in 4 different directions, so CF is landlocked by other postcode areas on most sides.
CF districts, settlements and water supply
| District | Principal settlement | Water company | Hosepipe ban status |
|---|---|---|---|
| CF3 | Cardiff | Welsh Water | No restrictions |
| CF5 | Cardiff | Welsh Water | No restrictions |
| CF10 | Cardiff | Welsh Water | No restrictions |
| CF11 | Cardiff | Welsh Water | No restrictions |
| CF14 | Cardiff | Welsh Water | No restrictions |
| CF15 | Caerphilly | Welsh Water | No restrictions |
| CF23 | Cardiff | Welsh Water | No restrictions |
| CF24 | Cardiff | Welsh Water | No restrictions |
| CF30 | Cardiff | Welsh Water | No restrictions |
| CF31 | Pen-y-bont ar Ogwr | Welsh Water | No restrictions |
| CF32 | Pontycymer | Welsh Water | No restrictions |
| CF33 | Porthcawl | Welsh Water | No restrictions |
| CF34 | Maesteg | Welsh Water | No restrictions |
| CF35 | Pencoed | Welsh Water | No restrictions |
| CF36 | Porthcawl | Welsh Water | No restrictions |
| CF37 | Pontypridd | Welsh Water | No restrictions |
| CF38 | Llantrisant | Welsh Water | No restrictions |
| CF39 | Porth | Welsh Water | No restrictions |
| CF40 | Tonypandy | Welsh Water | No restrictions |
| CF41 | Rhondda | Welsh Water | No restrictions |
| CF42 | Treorchy | Welsh Water | No restrictions |
| CF43 | Ferndale | Welsh Water | No restrictions |
| CF44 | Aberdare | Welsh Water | No restrictions |
| CF45 | Mountain Ash | Welsh Water | No restrictions |
| CF46 | Treharris | Welsh Water | No restrictions |
| CF47 | Merthyr Tydfil | Welsh Water | No restrictions |
| CF48 | Merthyr Tydfil | Welsh Water | No restrictions |
| CF61 | Llantwit Major | Welsh Water | No restrictions |
| CF62 | Barri | Welsh Water | No restrictions |
| CF63 | Barri | Welsh Water | No restrictions |
| CF64 | Penarth | Welsh Water | No restrictions |
| CF71 | Cowbridge | Welsh Water | No restrictions |
| CF72 | Talbot Green | Welsh Water | No restrictions |
| CF81 | Bargod | Welsh Water | No restrictions |
| CF82 | Ystrad Mynach | Welsh Water | No restrictions |
| CF83 | Caerphilly | Welsh Water | No restrictions |
| CF91 | Cardiff | Welsh Water | No restrictions |
| CF95 | Cardiff | Welsh Water | No restrictions |
| CF99 | Cardiff | Welsh Water | No restrictions |
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 CF
No water company covering CF 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 |
|---|---|---|---|---|
| CF3 | Not published by Welsh Water. Check with your supplier. | |||
| CF5 | Not published by Welsh Water. Check with your supplier. | |||
| CF10 | Not published by Welsh Water. Check with your supplier. | |||
| CF11 | Not published by Welsh Water. Check with your supplier. | |||
| CF14 | Not published by Welsh Water. Check with your supplier. | |||
| CF15 | Not published by Welsh Water. Check with your supplier. | |||
| CF23 | Not published by Welsh Water. Check with your supplier. | |||
| CF24 | Not published by Welsh Water. Check with your supplier. | |||
| CF30 | Not published by Welsh Water. Check with your supplier. | |||
| CF31 | Not published by Welsh Water. Check with your supplier. | |||
| CF32 | Not published by Welsh Water. Check with your supplier. | |||
| CF33 | Not published by Welsh Water. Check with your supplier. | |||
| CF34 | Not published by Welsh Water. Check with your supplier. | |||
| CF35 | Not published by Welsh Water. Check with your supplier. | |||
| CF36 | Not published by Welsh Water. Check with your supplier. | |||
| CF37 | Not published by Welsh Water. Check with your supplier. | |||
| CF38 | Not published by Welsh Water. Check with your supplier. | |||
| CF39 | Not published by Welsh Water. Check with your supplier. | |||
| CF40 | Not published by Welsh Water. Check with your supplier. | |||
| CF41 | Not published by Welsh Water. Check with your supplier. | |||
| CF42 | Not published by Welsh Water. Check with your supplier. | |||
| CF43 | Not published by Welsh Water. Check with your supplier. | |||
| CF44 | Not published by Welsh Water. Check with your supplier. | |||
| CF45 | Not published by Welsh Water. Check with your supplier. | |||
| CF46 | Not published by Welsh Water. Check with your supplier. | |||
| CF47 | Not published by Welsh Water. Check with your supplier. | |||
| CF48 | Not published by Welsh Water. Check with your supplier. | |||
| CF61 | Not published by Welsh Water. Check with your supplier. | |||
| CF62 | Not published by Welsh Water. Check with your supplier. | |||
| CF63 | Not published by Welsh Water. Check with your supplier. | |||
| CF64 | Not published by Welsh Water. Check with your supplier. | |||
| CF71 | Not published by Welsh Water. Check with your supplier. | |||
| CF72 | Not published by Welsh Water. Check with your supplier. | |||
| CF81 | Not published by Welsh Water. Check with your supplier. | |||
| CF82 | Not published by Welsh Water. Check with your supplier. | |||
| CF83 | Not published by Welsh Water. Check with your supplier. | |||
| CF91 | Not published by Welsh Water. Check with your supplier. | |||
| CF95 | Not published by Welsh Water. Check with your supplier. | |||
| CF99 | Not published by Welsh 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 CF 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 CF area?
There are 39 CF postcode districts, running from CF3 to CF99, and they contain 23,435 live postcodes across 154 sectors.
What towns does the CF postcode area cover?
CF covers Cardiff, Caerphilly, Merthyr Tydfil, Barri, Aberdare and Pen-y-bont ar Ogwr. The area takes its name from Cardiff, and each district is listed with its settlement in the table on this page.
Which water company supplies CF postcodes?
Welsh Water supplies all 39 CF 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 CF3 and CF5 both say Cardiff?
CF3, CF5, CF10, CF11, CF14, CF23, CF24, CF30, CF91, CF95 and CF99 all serve Cardiff, 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 CF postcode map?
Yes. This page offers the CF 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.
Which councils cover the CF postcode area?
CF reaches into Cardiff, the Vale of Glamorgan, Rhondda Cynon Taf, Bridgend, Caerphilly, Powys, Merthyr Tydfil and Newport. A postcode area is not a council area: they were drawn for different purposes and a single district can sit across a council boundary, so your postcode does not tell you which authority you pay.
Why is there no CF4 postcode district?
CF4 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.