Foundations
Part of Define the offer before staffing your content agency
Content agency market size in England: why no reliable figure exists
No official figure exists for the size of the content agency market in England. See why SIC codes and ONS data fall short, how published UK estimates conflict and how to build a labelled estimate.
Nobody publishes a reliable figure for the size of the content agency market in England. The official data counts businesses by industry code, not by what they do, and mostly reports the whole UK. Commercial estimates exist, but they define the market differently and disagree. This article shows where the gaps are and how to build a clearly labelled estimate.
Why the official data cannot isolate content agencies
The UK classifies businesses with Standard Industrial Classification (SIC) 2007 codes. There is no code for content marketing. A content agency may register under advertising agencies (73.11), public relations and communications (70.21) or another code, depending on how it described itself. The code tells you little about the services sold.
The Office for National Statistics (ONS) Annual Business Survey is the main source on turnover. Its five-digit extract for 2016 to 2023, released on 21 May 2025 as the Annual Business Survey by five-digit SIC code, reports turnover, purchases and approximate gross value added. It is a UK dataset, so it contains no England series for content agencies.
Three gaps in the data
- No boundary:advertising agencies, PR firms, SEO and web studios and freelancers all sell content work, and no official class separates it.
- No England cut:national turnover must be split by an allocation, such as employment share, that you choose and justify.
- No content ratio:nothing official says what share of an advertising agency's turnover is content work.
Directory listings do not fill these gaps. They support provider discovery, not measurement of market value. The market-entry checklist shows how to size a market for a decision without treating directory entries as a denominator.
National output series give context but not the answer. The ONS quarterly national accounts and its Index of Services track movement in services output. Neither isolates content agencies or gives an England total for them.
Published estimates disagree
Commercial publishers do estimate related markets, but their definitions differ. IBISWorld's July 2026 report puts UK advertising agencies (SIC 73.110) at £46.3 billion in 2026 and excludes public relations agencies and market researchers. Its separate March 2026 report on UK digital advertising agencies gives £24.7 billion for 2026 and covers search engine optimisation and digital display advertising.
Those two figures differ by almost half because the boundaries differ. Neither is England-only, and neither is a content-agency total. A buyer who quotes either as the size of the content agency market is quoting a different market. When you cite any estimate, record its publisher, year, geography and definition.
What a defensible estimate looks like
You can build a labelled estimate by working through the steps below. Only step 1 uses published data, and the other two shares are assumptions you must state.
Three-step England estimate method
- Start with national output figure
- Apply England share from employment data
- Narrow to content subset using stated ratio
- Publish a range, not a point figure
- Name year and source of every input
The figure numbers five steps. The first three are the calculation, and steps four and five are reporting rules.
- Start with a national figure with a stated boundary. This example uses IBISWorld's £46.3 billion for UK advertising agencies in 2026.
- Apply an England share. The share is an assumption here80 to 90 per cent, to be replaced by employment or turnover data you can cite.
- Apply a content ratio. Also an assumption5 to 15 per cent of turnover, to be replaced by a ratio you can evidence.
- Publish a range, not a single figure.
- Name the year and source of every input.
The mid-point is £46.3 billion × 85 per cent × 10 per cent, about £3.9 billion. The low case is 80 per cent and 5 per cent, about £1.9 billion. The high case is 90 per cent and 15 per cent, about £6.3 billion.
The range runs more than threefold. Nearly all of that spread comes from two unsourced shares, which is the problem in miniature: the national figure is published but the shares that decide the answer are not. The result is a labelled illustration of method, not a measured England market size.
Better data would change the answer
Three things would turn the estimate into a measurement. The first is an official content-marketing category, or a published ratio of content work within advertising and PR turnover. The second is an England-level turnover or employment cut at the five-digit SIC level, with the disclosure rules explained. The third is publishers using one stated boundary, so their figures can be compared.
Until then, treat any single England figure as an estimate with a stated method. Demand evidence can test whether a result looks plausible, but it does not add to market value. The demand signals that shape client budgets include search spend and hiring activity. The commercial opportunities analysis explains when sizing the market is worth doing at all.
Record the method
Keep a short methods note: the national series and its publication date, the England allocation and its source, the content ratio and its evidence, and the review date. Note the lookup route you used. The free data and paid panels comparison covers ONS, Google Trends and other sources, and tracing every number covers keeping them traceable. Refresh the calculation after an ONS revision or a new publisher estimate. To source a forecast, read how to source a content marketing outlook honestly.
