Foundations
Part of PR agency market foundations in England: evidence, service boundaries and delivery models
ONS and SIC 70210: limits for England PR market sizing
What ONS business counts and Companies House SIC 70210 can show about the pr agencies market size in england, and what they cannot establish.
ONS business counts and Companies House SIC 70210 can help describe the evidence available for PR market size in England, but they give neither the market's value nor the exact number of PR agencies. This article explains what those sources measure, why their counts are not a market total, and how to document a repeatable count. See the repeatable method for the part you can verify.
What to take away
- The ONS and Companies House sources give no PR agency market total for England.
- Companies House SIC code 70210 is the nearest label, but a filed code does not prove an entity trades as a PR agency.
- ONS counts enterprises and local units, and adding the two would double-count.
- The honest output may be a bounded count of verified records, not a market size.
- Do not apply an assumed PR share or England share to an all-industry total.
What the Companies House code covers
Companies House uses a condensed version of the full list of SIC codes from ONS, and only codes on that list may be used when filing. Code 70210 is described in its SIC code list as public relations and communications activities.
A filed code is supplied for a legal entity. It is a description of the company's nature of business, and it may be out of date or incomplete. It does not show what share of a company's income comes from PR, or whether it sells to clients in England.
What the ONS business data measures
The ONS bulletin titled UK business: activity, size and location gives UK business counts. There were 2.73 million VAT and/or PAYE businesses in the UK as of March 2025, up 0.4 per cent on March 2024. There were also 3.2 million sites, called local units.
The release was published on 24 September 2025 from a snapshot of the Inter-Departmental Business Register taken on 14 March 2025. In it, "business" means an enterprise: an organisational unit producing goods or services with a certain degree of autonomy in decision-making.
A local unit is an individual site within an enterprise. An agency with one office and two satellite sites is one enterprise and three local units, so the two counts must never be added together. The data can be reached through NOMIS, using its UK Business counts query.
Why a register is not a market
The ONS register covers VAT or PAYE registered businesses.
The whole-private-sector estimate combines unregistered businesses with registered ones from the business register, which shows how much a register alone can miss. The same statistics put 5.0 million private sector businesses in England across all industries.
Companies House can broaden identity research. Its company data product is a free monthly snapshot of information for live companies on the public register, including the SIC code. Register publication does not mean the code is verified.
A count that another researcher can repeat
Freeze a date and publish the protocol before extraction.
- Define the unit as a legal entity, enterprise, local unit or sole trader. Do not mix units.
- State the England rule separately for registered office, main operating site, buyer location and delivery location.
- Extract 70210 records from a dated Companies House snapshot, and the nearest ONS counts from NOMIS.
- Retain the original source and code, then reconcile company numbers, trading names, groups, duplicates and dissolved entities.
- Verify current first-party service evidence against the selection checklist eligibility rule, which separates PR from advertising and other services.
- Report eligible, excluded, duplicated, verified, unverified and non-responding records separately.
Do not total annual enterprise turnover. It may include other services and activity outside England. See the measurement mistakes article for the errors that follow.
An illustration of double counting
The figures below are invented to show why the units matter.
Unit / Count in the example
- Enterprises with code 70210
- 100
- Local units belonging to those enterprises
- 130
- Correct statement
- 100 enterprises operating from 130 sites
- Wrong total if added
- 230
The publication test
A result is publishable only if a second analyst can reproduce the frame, geography and exclusions from retained versions.
Stop if legal entities cannot be reconciled with trading names, if unregistered suppliers are silently omitted, or if current service scope cannot be verified. The honest finding may be that no defensible total exists. The demand signals article and the England market guide show what can be said instead.
This approach produces no count or valuation by itself. A business statistician and a commercial reviewer should examine the method before any figure is published. The review methodology page sets out how evidence is graded.
Before you act
- Freeze a date before extracting any records.
- Define the unit and do not mix units.
- State the England rule separately for each location type.
- Reconcile company numbers, trading names, groups and duplicates.
- Verify current first-party service evidence against an eligibility rule.
- Do not apply an assumed PR or England share.
Common questions
Why can't I just apply a percentage to an industry total?
A percentage applied to a broad total would only disguise an assumption. No official series measures the value or exact population of England's PR agency market, so the percentage would have no source.
What does the ONS business release measure?
The counts are enterprises and local units from a snapshot of the Inter-Departmental Business Register taken on 14 March 2025. An enterprise is a business, and a local unit is a site within it.
What must happen before any result is published?
A second analyst must be able to reproduce the frame, geography and exclusions from retained versions. Stop if entities cannot be reconciled or service scope cannot be verified.
