Full fibre reaches 58.4% of homes in Carmarthenshire, though only 7% of connections run at 300 Mbps or faster. Typical measured speed is 67 Mbps down and 18 Mbps up, 34% below the UK download average. 15 providers offer 206 broadband deals, up to 1,600 Mbps.
Deals for Carmarthenshire, checked and refreshed daily.
Best value broadband deal in Carmarthenshire
The best value in Carmarthenshire on full first-year cost is 4th Utility's 300Mb Full Fibre (24 Months): £240 across year one, about £20 a month. At 300 Mbps it copes with anything a household runs at once.
Best value in Carmarthenshire
£20/mo
for 12 months, then £40/mo
Cheapest broadband deal in Carmarthenshire
The cheapest deal in Carmarthenshire is Fibre 40 from Onestream at £18.50 a month for 40 Mbps. 4th Utility is essentially level at £20.00 a month. Well below the UK average, which shows on a busy evening.
Cheapest in Carmarthenshire
£18.50/mo
rises to £21.25 in April 2027 (+£2.75)
Runner-up on price
£20/mo
for 12 months, then £40/mo
Fastest broadband deal in Carmarthenshire
The fastest deal available in Carmarthenshire is Full Fibre 1.6GB from EE at 1,600 Mbps. Zen Internet matches it at the same top speed.
Fastest in Carmarthenshire
£38.99/mo
rises to £42.99 in March 2027 (+£4)
Runner-up on speed
£45/mo
No rises, no surprises.
Compare broadband deals in Carmarthenshire
£22.99/mo
rises to £26.99 in March 2027 (+£4)
£27.99/mo
rises to £31.99 in March 2027 (+£4)
£23/mo
No rises, no surprises.
£23/mo
No rises, no surprises.
Broadband providers in Carmarthenshire
15 providers serve Carmarthenshire including Virgin Media, Sky and BT, with EE the fastest at 1,600 Mbps.
Ranked by Ofcom complaints per 100,000 customers, fewest first. A down arrow is below the industry average, up is above, and a dash means Ofcom publishes no figure for that provider (usually because it is below Ofcom's 1.5% market-share reporting threshold). A small diagonal arrow shows the past-year trend (↘ improving, ↗ getting worse).
Ofcom records the typical Carmarthenshire download speed at 67 Mbps.
Upgrade nudge
Room to upgrade in Carmarthenshire
Only 7% of the 51,000 connections here are on 300Mbps or faster, even though 58% can get gigabit.
The faster line is already there. For most of these homes it is the contract holding them back, not the infrastructure.
Is your broadband good enough?
The typical Carmarthenshire line runs 67 Mbps.
Working from home
OKStreaming and family use
OKWhat speeds are people actually getting?
Gigabit reaches 58% of Carmarthenshire, and the fastest available is 1,000 Mbps. The full split by band is below.
What broadband coverage does Carmarthenshire have?
Superfast broadband reaches 78% of Carmarthenshire premises but gigabit only 58%, so around 20% of homes can get fast broadband but not the fastest.
Can I rely on mobile broadband in Carmarthenshire?
Outdoor 5G reaches 92% of Carmarthenshire, but 2% of homes get no indoor 4G from any network, so a mobile backup here wants a window.
The two 5G figures differ. “5G availability” is everyday 5G running on the existing 4G core, which is what most phones show. “Next-gen 5G” is standalone 5G: a full 5G network with lower lag, still reaching fewer places.
Broadband speeds by Carmarthenshire neighbourhood
Measured speeds range from 77 Mbps in Pembrey to 53 Mbps in Llanybydder, so your street matters more than the Carmarthenshire average.
| Neighbourhood | Median | vs area | Upload | Superfast | Gigabit | 5G |
|---|---|---|---|---|---|---|
| Pembrey SA16 | 77 | +10 | 24 | 90% | 87% | 92% |
| Carmarthen Town North and SA31 | 76 | +9 | 23 | 97% | 76% | 92% |
| Tyisha SA15 | 70 | +2 | 18 | 94% | 80% | 92% |
| Cenarth and Llangeler SA38 | 67 | 0 | 19 | 82% | 29% | 86% |
| Cilycwm SA19 | 67 | 0 | 16 | 47% | 30% | 92% |
| Llannon SA14 | 67 | 0 | 20 | 90% | 77% | 92% |
| Llandovery SA20 | 67 | -1 | 16 | 62% | 56% | 92% |
| Llanegwad SA32 | 63 | -4 | 17 | 54% | 33% | 92% |
| Ammanford SA18 | 62 | -5 | 16 | 89% | 72% | 93% |
| Kidwelly and St Ishmael SA17 | 61 | -6 | 15 | 81% | 47% | 92% |
| St Clears and Llansteffan SA33 | 58 | -10 | 15 | 65% | 33% | 92% |
| Whitland SA34 | 57 | -10 | 13 | 66% | 26% | 91% |
| Llanfihangel-ar-Arth SA39 | 54 | -13 | 14 | 72% | 64% | 90% |
| Llanybydder SA40 | 53 | -14 | 13 | 76% | 55% | 85% |
Measured Ofcom data per Carmarthenshire neighbourhood, ranked fastest first. Median and upload are in Mbps; vs area is the median difference from the Carmarthenshire average; superfast, gigabit and 5G are the % of premises covered. Swipe the table sideways for more columns.
Postcode districts in Carmarthenshire
Towns in Carmarthenshire
Nearby areas
Frequently asked questions
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Speed and coverage figures for Carmarthenshirecome from Ofcom's Connected Nations data, current to January 2026. Deal prices are pulled live from providers. Compiled by the FindBroadband team. See how we rank and source our data.