How to Check Broadband Before You Buy: Coverage Is Not Speed

Broadband is the utility most likely to be described on a property listing in words that sound like a measurement but are not one. “Gigabit available”, “superfast broadband”, “fibre to the area” — every one of those is a statement about what a network operator says it can supply to a premises, not about the speed anything currently runs at.

For anyone who works from home, that distinction is what matters most. Here is how the national data is built, what it can and cannot tell you, and the checks that actually resolve an address.

What Ofcom Connected Nations measures

Ofcom’s Connected Nations report is the authoritative national picture of fixed broadband in the UK. It is built from data supplied by network operators about where services are available, and it reports availability — the share of premises a network can serve — rather than speeds recorded at anybody’s router.

The tiers are defined by the download speed the technology is capable of delivering¹:

Tier	Ofcom definition
Superfast	30 Mbit/s or more
Ultrafast	300 Mbit/s or more
Gigabit-capable	1 Gbit/s or more
Full fibre (FTTP)	Fibre all the way to the premises

Separately, the broadband Universal Service Obligation gives eligible premises the right to request a “decent” connection, which Ofcom defines as at least 10 Mbit/s down and 1 Mbit/s up². That is a legal safety net, not a target — it sits well below what a two-person working household needs.

As at January 2026, Ofcom reported that 89% of UK residential premises — 27.1 million — had access to a gigabit-capable network, and 82% — 24.9 million — had access to full fibre¹.

Why “gigabit available” is not “gigabit delivered”

Four things sit between an availability figure and the number on your speed test.

Availability is about the network, not your contract. A gigabit-capable network passing the property means you can buy a gigabit package. It says nothing about what the current occupier bought, and nothing about what you will pay.

Copper distance still decides a lot. Where the last leg runs over copper from a street cabinet, actual speed falls with distance. Two houses on the same street, on the same technology, with the same provider, can return materially different speeds. This is the single biggest reason a postcode-level figure misleads at plot level.

Upload is asymmetric and under-reported. Headline tiers are download figures. On older technologies upload sits far below download, and upload is what video calls, cloud backups and large file transfers actually consume. A connection that streams fine can still make you the person who freezes in every meeting.

Coverage is reported against premises counts. A postcode where 90% of premises can get full fibre is not a postcode where your specific premises can. In small or mixed-development postcodes, the minority can be a single address — and it can be yours.

What our own broadband figures are — and are not

Home-Checker’s broadband data comes from Ofcom Connected Nations at postcode level. Every figure we show is a coverage percentage — the share of premises in that postcode where full fibre, gigabit, ultrafast or superfast service is available, plus the share still below the Universal Service Obligation.

They are not megabits. We do not publish a predicted speed for an address, because the source data does not contain one and we are not going to invent one. What the percentages are good for is a fast structural read: an outcode where 3% of premises have full fibre and 19% cannot reach 30 Mbit/s is a very different proposition from one at 77% full fibre — and those are both real ends of the Surrey range in our own data. You can see that before you book a viewing. Our analysis of Surrey postcodes with below-30 Mbit/s connectivity shows the spread inside a single county, and rural broadband in Surrey villages covers why the gaps sit where they do.

The checks that resolve a specific address

1. Run the address-level Ofcom broadband checker with the exact house number and postcode — not the postcode alone. Network operators publish free address-level checkers too, and it is worth running more than one.
2. Identify the technology, not the label. Full fibre to the premises is future-proof. Fibre to the cabinet is not, and its performance depends on how far you are from that cabinet.
3. Ask the seller what they actually get. A screenshot of a speed test from the property, taken at 8pm on a weekday, is worth more than any availability percentage. Ask for upload as well as download.
4. Look for alternative networks. Smaller providers build street by street and do not always appear on comparison tools. Search for build activity in the specific village or estate.
5. Check the flat-specific problem. In converted and purpose-built blocks, the network may reach the building without reaching every flat, and installing it can need freeholder consent.
6. Treat mobile as a separate question. Fixed-line availability tells you nothing about indoor mobile signal, and a rural property can be short of both.

Why this belongs in your viewing-stage checks

Broadband is not a snagging item you fix after moving in. Where a property sits on legacy copper with no build plan, there is often nothing to do about it for years — and a property that cannot support home working has a smaller buyer pool when you come to sell. It deserves the same viewing-stage attention as flood risk or the local market picture, and it is exactly the kind of gap that a listing will not fill for you — see what the listing won’t tell you.

For a county-level view of where the fastest connections cluster, see the fastest-broadband outcodes in Surrey and the county area data.

Broadband availability figures are sourced from Ofcom Connected Nations and reflect what operators report as available. Actual speeds depend on the package bought, the internal wiring and the router. Home-Checker is not a connectivity provider and does not guarantee speeds.

Run a Home-Checker report for any English postcode to see broadband coverage alongside schools, crime, flood risk and the local market in one document.

Footnotes

1. Ofcom, Connected Nations update: Spring 2026, published 13 May 2026, reporting network data as at January 2026; tier definitions from Ofcom, Connected Nations 2025 (published 19 November 2025). Superfast is defined as 30 Mbit/s or more, ultrafast as 300 Mbit/s or more, and gigabit-capable as 1 Gbit/s or more. ↩ ↩²

2. The broadband Universal Service Obligation gives eligible UK premises the right to request a “decent” connection, defined by Ofcom as at least 10 Mbit/s download and 1 Mbit/s upload. House of Commons Library, “The Universal Service Obligation (USO) for Broadband” (commonslibrary.parliament.uk/research-briefings/cbp-8146). ↩