How does the UK define SME and enterprise?
UK definitions follow the Companies Act 2006 and the ONS business size classifications. A micro-business has fewer than 10 employees. Small means 10 to 49 employees. Medium means 50 to 249 employees. Those three together form the SME category, meaning any business with fewer than 250 staff. Enterprise covers 250 employees and above, though there is no single statutory threshold at the upper end.
In practice, B2B data buyers and sales teams often apply their own working thresholds. A SaaS vendor targeting IT infrastructure budgets might define enterprise as 500 employees, because that is where dedicated IT procurement teams typically appear. A telecoms reseller might treat 100 employees as enterprise because the deal value changes materially at that headcount. The official ONS categories are a good default, but your commercial definition should be calibrated to where your proposition changes.
Companies House filings record employee count at the time of the most recent annual return, which can lag reality by 12 to 18 months at fast-growing firms. For targeting purposes, a data file compiled from Companies House and corporate web sources will include employee count as a filter, but verify the most critical accounts directly before committing significant sales time.
Enterprise vs SMB: a side-by-side comparison
| Dimension | SMB (under 250 employees) | Enterprise (250+ employees) |
|---|---|---|
| UK universe size | Approx. 5.5 million businesses (99%+ of all UK firms) | Approx. 8,000-9,000 businesses (less than 0.5% of all UK firms) |
| Decision-maker structure | Usually 1 person (owner, MD, or department head with full authority) | Buying committee of 5 to 10: primary buyer, technical evaluator, finance, end-user champion, C-suite sponsor |
| Typical sales cycle | 1 to 12 weeks | 6 to 18 months |
| Data depth needed | 1 to 2 contacts per company; direct email and/or telephone | 5 to 10 named contacts per account across multiple functions and seniority levels |
| Per-record cost (verified) | £0.05 to £0.25 for standard email contact | £0.30 to £0.80 for verified named contact with direct dial and mobile |
| Primary outreach channels | Email (high volume), telephone, postal for local/regional campaigns | Account-based: direct mail, telephone, personalised email sequences across multiple contacts |
| Message emphasis | Speed to value, simplicity, cost savings, quick ROI | Formal business case, risk mitigation, integration capability, references and case studies |
| Data decay rate | High: SMB contact churn often 25-35% annually due to business closures and pivots | Lower at account level (large firms persist longer), but individual contact churn still 20-25% annually |
| SIC code targeting | Broad industry filtering (e.g. all SIC division G: retail trade) | Precise SIC targeting combined with specific job function filters (e.g. SIC 62010 + IT Director) |
| Lawful basis (UK GDPR) | Legitimate interests assessment required; TPS wash for telephone; ICO guidance applies | Same: legitimate interests, LIA, TPS suppression. More complex where multi-jurisdiction buying committees exist. |
Why does enterprise targeting require buying-committee data?
The single biggest mistake in enterprise outreach is treating a 5,000-employee organisation the same way you would a 30-person accountancy practice. Large organisations separate authority across functions. A Finance Director at a 2,000-person logistics company cannot sign off a £150,000 software contract without sign-off from IT security, legal, and a procurement committee. Cold email to one person, however accurate and well-crafted, has a near-zero conversion rate because your message sits in one inbox while 5 other people who need to agree have never heard of you.
Effective enterprise data files are built around the account as a unit. For a target account, you want contacts across at least three of the following five roles: the primary buyer (who holds budget and initiates the search), the technical evaluator (who assesses fit), the finance approver (who checks the business case), the end-user champion (who advocates internally), and the executive sponsor (who provides political cover and can accelerate or kill the deal). In a manufacturing company with 600 staff, those five roles might sit with the Operations Director, Head of IT, CFO, a senior production manager, and the CEO respectively.
Our B2B data, compiled under legitimate interests from publicly available sources, covers job function and seniority at the contact level, which means you can pull all five roles for a named account rather than just the most obvious title. For a worked example of how seniority filters interact with job function in practice, see our guide on B2B job function and seniority targeting.
How do channel preferences differ by segment?
SMB outreach: volume and speed
SMBs are best reached at volume. A Yorkshire-based pest-control supplier selling franchise opportunities might target all food-manufacturing businesses with 20 to 100 staff across the North of England: that could be 4,000 companies. Email is the natural lead channel because the cost per contact is low, the decision-maker is usually reachable on a single address, and response cycles are short. Telephone follow-up for responders or non-openers adds a second touch without large incremental cost.
Postal direct mail works well for SMBs in trades and local services, where the owner is less likely to be glued to email and a physical letter from a credible sender still carries authority. The cost per piece is higher (typically £1 to £3 including postage, print, and fulfilment), so postal works best where the deal value justifies it or where the target audience is known to be email-resistant.
Enterprise outreach: account-based sequencing
Enterprise selling demands patience and coordination. Sending a cold email blast to 200 enterprise accounts and waiting for replies is not an enterprise strategy. Account-based marketing (ABM) means selecting a defined set of target accounts, mapping the contacts within each, and running personalised sequences across multiple channels simultaneously.
In our experience, response rates on cold direct mail to verified C-suite contacts at enterprise accounts beat cold email alone by a factor of 3 to 5 in regulated sectors such as financial services and healthcare. A physical letter to a CFO at a 1,500-person insurance firm, personalised with the company name and a specific reference to a business challenge, reaches someone who has largely tuned out cold email. Pair it with a follow-up telephone call to their direct dial two to three days after the letter's estimated delivery and you have a two-touch, two-channel sequence before any email has been sent.
For account-based approaches at larger organisations, the data architecture matters as much as the message. See our article on ABM data in the UK for how to structure an account-level contact file for multi-stakeholder campaigns.
What are the most common targeting mistakes?
Using SMB data for enterprise outreach
The most frequent error is purchasing a broad contact file, which often defaults to one contact per company, and then targeting the enterprise segment with it. The file might correctly identify that Rolls-Royce plc is in your target SIC code and return the name of a Procurement Manager. But Rolls-Royce has approximately 40,000 employees and a purchasing process involving legal, IT security, ESG compliance, and executive sponsorship. Reaching one mid-level contact with a one-touch email campaign is not enterprise outreach; it is SMB tactics applied to the wrong target universe.
Using enterprise data depth for SMB campaigns
The opposite error is equally wasteful. If you are selling payroll software to businesses with 5 to 49 employees, you do not need seven contacts per account at different seniority levels. The sole director of a 12-person cleaning company is the decision-maker, the finance approver, the IT evaluator, and the end-user champion all in one. Buying deep buying-committee data for that target universe inflates your data cost significantly and produces duplicate outreach to the same person under different job titles.
Getting the message wrong by segment
Data quality aside, the message calibration is a separate failure mode. SMB owners respond to speed and simplicity. "Up and running in 48 hours, no IT team needed, cancel any time" is a message that lands. Enterprise buyers need formal business cases, integration evidence, security certifications, and reference customers in their sector. A message written for an SMB owner ("quick setup, no fuss") sent to a Head of Digital Transformation at a 3,000-person retailer signals that you do not understand enterprise procurement. The reverse is equally off: a dense ROI model sent to a sole trader who just needs a quote by Thursday will produce silence.
Where does mid-market fit?
Mid-market is the awkward middle: typically 100 to 499 employees in UK terms, though some sectors push this to 50 to 999. It has characteristics of both segments. A 200-person professional-services firm will have a buying committee, but it is likely 2 to 4 people rather than 8 to 10. Sales cycles run 2 to 6 months rather than 6 to 18. Data depth should cover 3 to 5 named contacts per account: the senior functional buyer, a technical stakeholder, and a finance sign-off.
The mistake many sales teams make is forcing mid-market accounts into whichever playbook is easiest to run. Treating a 180-person engineering consultancy like an SMB (single contact, fast email sequence) under-invests in the relationship. Treating it as a full enterprise account (10-contact ABM sequence, 12-month nurture cadence) over-invests and burns resource on a deal that might close in 10 weeks if handled efficiently. Mid-market deserves its own segmentation within your target list. For an idea of the C-suite contact coverage available at that size, our article on C-suite contact data in the UK covers what is realistically available at different headcount bands.
Per-record pricing by segment: what to budget
Pricing varies with data depth and verification level. The figures below reflect typical market ranges for UK B2B contact data compiled under legitimate interests from public sources.
For SMB contacts, expect to pay £0.05 to £0.15 per record for a basic email-only contact file at scale (5,000 records or more). Add telephone numbers and the range moves to £0.10 to £0.25. Verified mobile numbers are expensive to compile and verify; SMB mobile data is less commonly available and commands a premium where it exists.
For enterprise contacts with verified direct dials and business mobile numbers, pricing typically runs £0.30 to £0.80 per record. The higher end applies to hard-to-find functions (CISO, Chief Data Officer, Head of Procurement at FTSE 500 firms) where the universe is small and verification is labour-intensive. Mid-market contacts with telephone fall between the two, roughly £0.15 to £0.40.
Volume discounts apply at scale, but the relationship is non-linear: a 50,000-record SMB file will attract a better per-record rate than 500 enterprise records, purely because the latter requires more manual verification per record. Budget accordingly when comparing segments.
Data decay and refresh frequency
SMB contact data decays faster than enterprise data, largely because small businesses close, pivot, or change ownership at higher rates. UK business closure rates run at roughly 10-13% annually for small businesses, meaning a 10,000-record SMB file can have 1,000 to 1,300 defunct companies within 12 months. Enterprise accounts are more persistent, but individual contact churn (job changes, promotions, departures) still runs 20-25% annually. Build refresh cycles into your campaign planning rather than treating a data file as a static asset.
For a broader look at how UK B2B data targeting by company size interacts with industry and geography, our guide on small business data in the UK covers the SMB segment in more depth.