Cheapest full fibre deals: how to find one that lasts

The cheapest full fibre deals sound too good the first time you see them, and the instinct to distrust them is fair. A network you had never heard of offering more speed for less money than the household name you have paid for years invites the obvious question: where is the catch? Sometimes there is one, hidden in the terms rather than the price. Often there genuinely is not, and the low price is just what happens when a company owns its own fibre. This guide is how to tell the two apart.

Where are the cheapest full fibre deals actually found?

Usually on the alternative networks, not the big brands. An altnet has laid its own fibre into the ground and to your door, so it is not paying a wholesale fee to rent the Openreach network that BT, Sky, TalkTalk and Vodafone mostly share. That structural difference, which our guide on altnets versus Openreach explains in full, is why the lowest prices for genuine full fibre tend to come from names you may not recognise.

Across the networks we track, entry-level full fibre generally sits somewhere from around £15 to £25 a month, with the exact floor depending on which networks reach your street. That is why we do not print a single magic number here. It would be out of date within weeks, and the real one is only ever the price available at your address.

Prices also vary more than you might expect from one street to the next, because they depend on how many networks compete for your address. A postcode reached by two or three altnets tends to see keener deals than one reached by a single network, for the same reason any market does. That is worth knowing before you assume a friend's price a few miles away is the one you will be offered.

Why the headline price is not the price you pay

The advertised figure is the beginning of the sum. Three things quietly change what the deal really costs over its life, and a genuinely cheap headline can lose to a dearer one on all three.

• The price after the offer. A low introductory rate that steps up at month twelve is a different deal from a flat one. Read what it becomes, not just what it starts at.
• Annual rises. Some networks fix your price for the whole term; others raise it every year. Since January 2025, Ofcom has required any in-contract increase to be shown upfront as a fixed pound amount, so a rising deal cannot hide it. Our guide to broadband price rises covers how to weigh it.
• Setup and activation fees. A cheap monthly price with a fee on top may cost more in year one than a slightly higher price with free setup. Add the fee in before you compare.

The cheap deals that come with a catch

Not every low price is a clean one, and the catches are worth knowing so you can spot them.

• A data cap. Most full fibre is unlimited, but the very cheapest tier from a few networks limits your monthly usage. Fine for light use, a problem for a streaming household.
• A price that only holds for a year. The cheapest twelve-month figure sometimes assumes a discount that falls away, leaving a standard price that is no longer a bargain.
• The rolling-month premium. No-contract freedom costs more per month, which can be worth it or wasted depending on your plans. Our guide to no contract broadband works through when the premium pays for itself.

How to find the cheapest deal that reaches you

The cheapest deal in the country is no use if it does not serve your street, so the search runs in a particular order.

• Check availability first. Start with which networks reach your address. Everything else applies only to the ones that come back.
• Match the speed to the house. The cheapest tier is usually the slowest, and for many homes that is plenty. Do not pay for a gigabit you will never stretch.
• Compare the whole-term cost. Put the deals that reach you side by side on the comparison table and total each one across the full contract, fees and rises included.

Is the cheapest always the best value?

Not reliably. Value is the lowest total cost for the speed and terms you actually want, and the very cheapest headline sometimes buys a data cap, a price that leaps in year two, or a network too new to trust with a long tie-in. A deal a couple of pounds dearer with a fixed price and free setup can be the better buy once you add it all up.

There is a simple test that cuts through most of it. Work out what each deal costs in total over the contract, add any setup fee, add any scheduled rises, and divide by the number of months. That single figure, the true monthly cost, is what you are actually comparing, and it often reorders a shortlist that looked settled on the headline price alone. The cheapest advert and the cheapest deal are frequently not the same line.

If your budget is genuinely tight, there is a cheaper route worth knowing about. Many providers offer social tariffs, heavily discounted packages for households on Universal Credit, Pension Credit and some other benefits, and they are often not advertised where the headline deals are.

Where to start

Availability first, price second. Find what is available where you live, read the profiles of the networks that reach you, and compare their deals over the whole term rather than the first month. The cheapest full fibre worth having is the lowest total cost among the networks that actually reach your door, not the boldest number on any advert.

Frequently asked questions

How cheap can full fibre actually get?

On the alternative networks we track, entry-level full fibre generally runs from around £15 to £25 a month, sometimes less on a promotion. The exact floor moves with the deals of the day and with which networks reach you, so treat any single figure as a snapshot rather than a promise, and check the comparison table for what is live now.

Why is altnet full fibre cheaper than BT or Sky?

Because altnets built their own fibre rather than renting the Openreach network that most big brands share, so they are not paying a wholesale fee on every line. That saving, plus the need to win customers on unfamiliar names, tends to show up as a lower price for the same or a faster speed.

Is the cheapest deal always the best value?

Not always. A rock-bottom headline that jumps after twelve months, adds a setup fee, or rises every April can cost more over the term than a slightly dearer deal with a fixed price. Compare the total across the whole contract, not the first month.

Are there cheaper options if money is tight?

Yes. Many providers offer social tariffs, which are heavily discounted packages for households on Universal Credit, Pension Credit and some other benefits. They are not always advertised prominently, so it is worth asking a provider directly or checking Ofcom's list of who offers one.

Does cheap full fibre mean slow full fibre?

No. The cheapest tier is usually the slowest a network sells, often around 100 to 150 Mbps, but that is full fibre all the way to your home and is plenty for most households. You are paying less for less speed, not for a worse connection.