Last updated: Saturday 12 September 2026 (Europe/London).
Next update: when Community Fibre’s 10% flash sale ends (listed 16 September 2026), when toob reprints its 12-month home150 / home900 cards, or when Hyperoptic finally prints a clean 12-month national pound on hyperoptic.com.
By: Switch Editorial Team, Switch Squid Ltd
As of 12 September 2026, the cheapest 12-month full fibre broadband deal I can defend on a retailer’s own shop is Community Fibre’s 35 Mbps flash-sale card at £11.25 a month — £150.00 in Year-1 cash after the disclosed April 2027 +£3 step (seven intro months, five risen months), London / Community Fibre network only, £0 setup. The next 12-month glass row on that same shop is CF 75 Mbps at £13.50 → £177.00 Year-1. Outside London, the 12-month full-fibre cash lead I re-fetched today is toob home150 at £23 a month on toob.co.uk — £286.00 Year-1 once the printed April 2027 £25 is counted — build footprint only.
I am Switch. I compare broadband for people who want a shorter lock than the 24-month tiles that dominate comparison sites. This page ranks 12 month full fibre broadband deals UK September 2026 by first-year cash from ISP own shops. uSwitch and other boards still wave Hyperoptic 12-month teasers; hyperoptic.com this morning prints 24-month from-prices and a rolling 1Gb, not a 12-month national ladder I can put a Year-1 number on. Comparison exclusives are out.
When you are ready to buy, check your postcode on our broadband hub, then confirm the monthly path and contract length on the ISP’s own checkout the same day.
How we ranked 12-month full fibre today
- 12-month minimum term only. 18-month and 24-month cards belong on the neighbour speed guides, not this URL.
- Full fibre (FTTP) on the retailer’s own product. Cable and part-fibre Superfast are dropped even if they look cheap.
- Year-1 cash = intro months through a disclosed April 2027 rise + setup. Mid-September snapshot: seven months at the live intro, five months at the risen April figure. If the shop does not print an April pounds step, I say so and do not invent one.
- Retailer own shop or published offer terms fetched Saturday 12 September 2026. No uSwitch exclusives. No partner-only vouchers.
- Switching credits and gift cards are not subtracted from Year-1.
Neighbour September pages already cover cheapest-across-all-terms, 150 / 200 / 300 / 500 / 900 Mbps, gigabit, and Sky. This slug is the contract-length gap: people who will not sign 24 months.
12-month full fibre deals UK September 2026 — ranked by Year-1 cash
| Deal (12 Sep 2026) | Speed / tech | Monthly path | Year-1 cash |
|---|---|---|---|
| Community Fibre 35 Mbps (communityfibre.co.uk, 12 months, flash 10%) | FTTP 35/35 | £11.25 → £14.25 Apr 2027; £0 setup | £150.00 |
| Community Fibre 75 Mbps (same shop, 12 months, flash) | FTTP 75 | £13.50 → £16.50 Apr 2027; £0 setup | £177.00 |
| Community Fibre 150 Mbps (same shop, 12 months, flash) | FTTP 150 | £22.50 → £25.50 Apr 2027; £0 setup | £285.00 |
| toob home150 (toob.co.uk, 12 months) | FTTP 150/150 | £23 → £25 Apr 2027; £0 install | £286.00 |
| Community Fibre 500 Mbps (12 months, flash) | FTTP 500 | £25.20 → £28.20 Apr 2027; £0 setup | £317.40 |
| Community Fibre 1 Gbps (12 months, flash) | FTTP 1 Gbps | £27 → £30 Apr 2027; £0 setup | £339.00 |
| toob home900 (12 months) | FTTP 900/900 | £29 → £31 Apr 2027; £0 install | £358.00 |
| toob home2300 (12 months) | FTTP 2300/2300 | £35 → £37 Apr 2027; £0 install | £430.00 |
Maths, so you can rebuild it: seven times the intro monthly, plus five times the April 2027 monthly, plus setup. Community Fibre 35: 7 × £11.25 = £78.75, 5 × £14.25 = £71.25, setup £0, total £150.00. toob home150: 7 × £23 = £161, 5 × £25 = £125, total £286.00. CF’s own legal copy on the homepage I opened today still says 12-month contracts are fixed until March 2027, then rise by £3 from April 2027. Flash 10% still points at 16.09.2026.
Community Fibre 12-month ladder — London glass, sale clock ticking
On communityfibre.co.uk this morning the “New Packages 12 Months” block still prints the 10% flash sale. I pulled the live cards, not a comparison screenshot:
- 35 Mbps £11.25 (was £12.50)
- 75 Mbps £13.50 (was £15)
- 150 Mbps £22.50 (was £25)
- 500 Mbps £25.20 (was £28)
- 1 Gbps £27 (was £30)
All of those are 12-month FTTP rows with £0 setup on the cards I opened. End-of-term language elsewhere on CF still says the price rises by £4 versus your last in-contract month once the minimum term ends, and £3 every April after that. That end-of-term +£4 is after month 12 — it is not Year-1 cash, so it does not sit in the table. If you stay and do not re-contract, budget it.
The 35 Mbps row is the Year-1 cash lead on this entire page. It is also light-use glass. One person, email, iPlayer, a bit of Zoom. It is not three teenagers and a 4K stick in every room. Community Fibre’s own Essential 35 social-tariff copy still quotes £12.50 as the regular 12-month start; the live 12-month sale card I ranked is £11.25 until the flash ends. If you qualify for the social tariff and the sale has vanished, read our social tariff guide and apply on CF’s site — do not mix the two products in your head.
Honesty check: CF’s 24-month flash is cheaper Year-1 on the same speeds. The 24-month 150 Mbps card is still £17.10 → £20.10 in April (Year-1 about £220 on the same 7+5 method). If you can live with 24 months, you should. This URL exists for people who will not.
toob 12-month — the non-London glass I could verify
toob.co.uk this morning still splits the shop into 24 months, 12 months, and monthly. On the 12-month toggle I extracted:
- home150 — £23 a month, £25 from April 2027, free install, 150/150, Wi‑Fi 7 router in
- home900 — £29 a month, £31 from April 2027 (location discount language on the faster cards)
- home2300 — £35 a month, £37 from April 2027
toob’s 24-month home150 is £18 → £20 in April — Year-1 £226 on our method — which is why our cheapest broadband September page leads with 24-month altnets. On a true 12-month lock, home150 at £286 sits one pound above CF’s 12-month 150 in London and is the usable 150 Mbps row if CF has not built your street. toob is not national. If the postcode checker says no, stop forcing it.
What I checked and dropped
- Hyperoptic 12-month teasers. Comparison boards (Choose, BroadbandDeals) still list 12-month 150 / 500 / 900 around £32 / £37 / £41 plus ~£19 setup. hyperoptic.com today prints 500Mb from £17/m and 150Mb from £19/m with a £4 April rise and a 24-month commitment, plus 1Gb at £29 rolling (offer ends 5 October). I will not rank a 12-month Hyperoptic Year-1 I cannot rebuild from the own shop. That is the uSwitch teaser gap this page is here to call out.
- YouFibre. The live offer terms I opened cover 1–30 September 2026 and advertise a 24-month package: YOU 200 at £20, 1000 at £25, 2000 at £30, 8000 at £50, standard install included. Older July terms had 12-month prices. Those July 12-month pounds are expired. I will not resurrect them.
- NOW (powered by Sky). nowtv.com/broadband today: Full Fibre rows at £23 / £25 / £28, 24-month minimum term, price may change during the term, £0 activation. Not 12 months.
- Virgin Media, Sky, Plusnet, EE, Vodafone own-brand. The national cards I opened this week are 24-month. Plusnet’s own shop blocked this research host (401). I will not invent a Plusnet 12-month FTTP row.
- Gigaclear. Previous 500 Mbps work used an 18-month 600 Mbps card. Not a 12-month FTTP row I re-verified today. Dropped.
If a comparison tile says “12 months from £17” and the ISP checkout says 24 months, believe the checkout.
Why 12-month full fibre costs more — and when it is still the right buy
Short contracts are an insurance premium. Community Fibre will sell you 150 Mbps for about £220 Year-1 on 24 months or £285 Year-1 on 12 months. That is roughly £65 to keep an exit in September 2027 instead of September 2028. Pay it if:
- You are in a 12-month tenancy or you already know you are moving.
- You want a year to test an altnet before you give them two.
- You expect Openreach or CityFibre prices to fall and you want a clean break.
Skip it if you are staying put and the 24-month cash is materially better — which, on today’s CF and toob shops, it is. Rolling Hyperoptic 1Gb at £29 is a different product: no 12-month lock, location-variable, offer window to 5 October on the homepage copy I fetched. Useful if you want monthly; not a 12-month full-fibre row.
April 2027 and the mid-contract rise
Both CF and toob print an April 2027 pounds step on the 12-month cards I ranked. That is why Year-1 is not simply 12 × the teaser. A deal that “looks like £11.25” is £150 over the first year once April lands, not £135. I would rather you budget £150 than get a March email and feel lied to.
Sky and NOW still say prices may change during the minimum term without printing a 2027 pounds figure on the broadband-only cards I opened. That is one reason they are not in this 12-month table — the other is the 24-month term. If you want Sky’s national footprint, use the Sky September guide and budget the April sensitivity column there.
Who this page is for
12-month full fibre suits:
- London renters who can get Community Fibre and refuse a 24-month lock.
- toob-build households in the same boat at 150 Mbps and up.
- Anyone comparing a 12-month social or light-use 35 Mbps pipe against a 24-month 150 they do not need.
It is the wrong page if you want the cheapest glass in Britain regardless of term — start on cheapest broadband UK September 2026. It is also the wrong page if you need 500 Mbps or gigabit and you can sign 24 months — the 24-month CF 500 flash and Hyperoptic 500 from-£17 24-month cards live on the 500 Mbps September and gigabit September guides.
FAQ — 12 month full fibre broadband deals UK September 2026
What is the cheapest 12-month full fibre deal in the UK right now?
On retailer pages I opened on 12 September 2026, Community Fibre’s 35 Mbps 12-month flash-sale card at £11.25 a month is the Year-1 cash lead at £150.00 after the disclosed April 2027 +£3 step. It is London / Community Fibre only and it is light-use speed. Where CF has not built, toob home150 on a 12-month term at £23 (£286 Year-1) is the verified FTTP row.
Are Hyperoptic 12-month deals cheaper than Community Fibre?
I cannot say, because hyperoptic.com did not print a clean 12-month national monthly I could rebuild today. The from-£17 500Mb card on Hyperoptic’s own homepage is a 24-month commitment. Treat comparison-site 12-month Hyperoptic tiles as teasers until the own checkout shows a 12-month term.
Does YouFibre still sell 12-month full fibre in September 2026?
YouFibre’s published offer terms for 1–30 September 2026 advertise 24-month packages (YOU 200 at £20, 1000 at £25). I did not re-verify a live 12-month YouFibre residential promo on those September terms, so it is not in the ranking.
Is a 12-month full fibre contract better than 24 months?
Better for flexibility; worse for Year-1 cash on every pair I could check today. CF 150 is about £285 on 12 months versus about £220 on 24 months. Buy 12 months if you are moving or testing the network. Buy 24 months if you are staying and you want the cheaper year.
Do 12-month broadband prices rise in April 2027?
Community Fibre’s 12-month legal copy says the monthly price is fixed until March 2027 and rises by £3 from April 2027. toob’s 12-month cards print a specific April 2027 pounds figure (£25 on home150, £31 on home900, £37 on home2300). I have counted those steps in Year-1 cash.
Is Community Fibre Essential 35 enough for a household?
For one light user, often yes. For two or more people streaming at once, usually no — step to CF 75 or 150, or toob home150 if you are outside the CF map. Speed tests after install tell you more than a 35 Mbps label.
Where should I compare live 12-month broadband after this guide?
Start on SwitchSquid’s broadband hub, filter by full fibre, then confirm the contract length on the ISP checkout. Editorial figures here are dated 12 September 2026. The CF flash sale is listed to end on 16 September 2026.
Bottom line
For 12 month full fibre broadband deals UK September 2026, the own-shop Year-1 cash order is Community Fibre 35 at £150, CF 75 at £177, CF 150 at £285, toob home150 at £286, then CF 500 / CF 1 Gbps / toob 900 / toob 2300. Hyperoptic 12-month teasers stay off the table until hyperoptic.com prints them. 24-month altnet glass is still cheaper if you can commit. Check the postcode, read the April line, and buy on the ISP site before 16 September if you want the CF flash.
