UK B2B Market Size Calculator
How many UK businesses can you actually reach? Select your target regions and get a source-backed total addressable market (TAM) in seconds — based on official ONS business demography data, not guesswork.
Quick answer
The UK had 2,860,000 active businesses in 2024 (ONS) — the upper bound of a UK-wide B2B total addressable market. A further 317,000 brand-new businesses were created that year, a renewable pool of fresh prospects with no incumbent vendor. London is the largest single regional market with 595,000 active businesses. Use the calculator below to size your own addressable market by region.
Estimate your UK market size
Your addressable UK market (12 regions)
The 318,000 business births in your selection are genuinely new enterprises each year — a renewable, time-sensitive pool of prospects that did not exist twelve months earlier. Source: ONS Business demography 2024 (OGL v3); figures are rounded to the nearest thousand.
Turn this market into a scored, sequenced outreach list.
See how GeraReach worksHow to use this for TAM, SAM and SOM
1. Size your TAM. Select every region you could sell into. The active business total is the geographic ceiling of your UK total addressable market.
2. Narrow to your SAM. Real ICPs are not “every business”. Apply your sector, company-size and intent filters to the regional total to estimate your serviceable addressable market. The ICP definition guide walks through the filters that matter.
3. Plan your SOM. Decide what share you can realistically win this year, then size the outreach volume to hit it. The annual business-births figure tells you how much of your market refreshes every twelve months.
Frequently asked questions
How many businesses can I reach in the UK?
There were 2,860,000 active businesses in the UK in 2024, according to the Office for National Statistics. That is the upper bound of a UK-wide total addressable market (TAM). Your true addressable market is the subset that matches your ideal customer profile — by region, sector, and size. Use the calculator above to size the regional component, then narrow by your other fit criteria.
What is the difference between TAM, SAM and SOM?
TAM (total addressable market) is everyone who could theoretically buy — for UK B2B, the full population of active businesses. SAM (serviceable addressable market) is the slice you can actually serve given your geography, product and ICP. SOM (serviceable obtainable market) is the share you can realistically win in a given period. This calculator gives you a defensible, source-backed starting point for the geographic dimension of TAM and SAM.
Why do new business births matter for outreach?
New "business births" are genuinely new enterprises created in a year — 317,000 across the UK in 2024. For an outreach team they are a renewable, time-sensitive prospect pool: a new business has no incumbent vendor for most categories, so reaching it early is disproportionately valuable. The calculator sums births across your selected regions so you can size that annual fresh-prospect flow.
Where does the data come from and can I trust it?
Every figure comes from "Office for National Statistics — Business demography, UK: 2024", published by the Office for National Statistics (ONS) on 2025-11-20 under the Open Government Licence v3.0 (OGL v3) (Crown copyright). ONS rounds counts to the nearest thousand, and the regional figures sum to the UK total. We do not estimate or model any numbers — the calculator only adds up the regions you select.
Which UK region has the most businesses to target?
London has the largest active business population of any UK region or nation (595,000 active businesses in 2024), making it the single largest regional B2B market in the UK. London and the South East together account for a large share of all UK enterprises.
Go deeper
Source: Office for National Statistics — Business demography, UK: 2024, Office for National Statistics (ONS). Released 2025-11-20. ONS bulletin.
Licence: Open Government Licence v3.0 (OGL v3) — Crown copyright. Figures rounded by ONS to the nearest thousand. Regional counts sum to the UK total (verified). This tool performs no modelling; it only sums the regions you select.
Page last reviewed 2026-06-27.