When to check affiliate marketing market size in England before planning

What to take away

No official statistic measures the affiliate marketing market size in England. Any number you use has to be built by you from named sources and a fixed definition.
The closest dated proxy is the ONS retail sales bulletin for January 2025, which reported a 1.7% monthly rise in Great Britain sales volumes. It covers retail, not commission.
Check the figures at four momentsannual budget setting, Q4 planning, network contract renewal, and each new ONS release.
Fix the scope, the period and the treatment of returns before you compare any two figures.

The England market size answer

Neither the ONS nor the ASA publishes an England-only value for affiliate marketing. The ONS measures retail sales across Great Britain in its monthly Retail sales, Great Britain bulletin, and the ASA regulates advertising content rather than trade value. The industry body IAB UK publishes the UK's digital adspend study, but that counts advertising spend rather than affiliate commission.

What exists are proxies. GB retail sales give demand context. Network payout totals give an order of magnitude for commissions: pull them from your own accounts at Awin, CJ Affiliate, Impact, Rakuten Advertising, Tradedoubler and Amazon Associates, while remembering that most networks report globally rather than for England. Your own commission statements give the narrow measure.

Some networks publish annual reports and benchmark material of their own, such as the Awin Report, and every network gives you programme-level tracked sales and payout totals for your own account. Those totals are rarely split by nation, and publication dates vary.

If you rebuild the figure from scratch, settle four scope decisions first: whether you count commission on tracked sales only or voucher-led and cashback programmes too; the reporting period; the treatment of returns, cancellations and reversals; and whether programmes outside your own network accounts count.

Proxy figures that can stand in

Proxy	What it measures	Coverage	Frequency
ONS retail sales	Retail sales volumes and value	Great Britain	Monthly
Network payout totals	Commission paid to publishers	Global or UK	Annual, irregular
Your commission data	Commission you paid	Your programme	Monthly
ASA rulings	Disclosure compliance	UK	Ongoing

Definition choices change the total, so record scope and period before you quote anything. A commission-only programme run through Awin or CJ Affiliate and a voucher-led or cashback deal on Quidco, TopCashback or VoucherCodes sit at very different values, so state which of them your figure includes.

Narrow vs Wide Market Size

Narrow definition

Commission scope: Tracked payouts only
Time frame: Monthly snapshot
Geography: National retail totals
Source: Network report

Wide definition

Commission scope: Adds voucher and loyalty
Time frame: Annual with seasonal peaks
Geography: Regional demand patterns
Source: ONS retail sales data

Example: scaling GB figures to an England estimate

Use one method and repeat it. A workable sequence:

Take the GB retail value for the period you need from the ONS monthly retail sales bulletin.
Multiply by England's population share of Great Britain, about 87% at the 2021 Census, using ONS population estimates, as a first cut.
Apply a commission rate taken from your own programme, not from a retail average.
Record the date, the sources and the adjustments so the next update repeats the same method.

Population share is a starting point only. Retail spend per head differs by region, so treat the result as an order-of-magnitude estimate.

Which model you run changes the base you scale. Commission-only programmes pay a commission on tracked sales, while voucher-led and cashback programmes give most of the commission back to the user, so they can show a larger sales volume for a similar payout.

Timing triggers before you plan

Four triggers matter:

autumn before the new financial year
.
Q4
planning for Black Friday and Christmas, when commission rates and placements are agreed.
contract renewal
, when tiers and cookie windows change.
about two weeks after the month ends
.

If none of these is near, one check before you commit spend is enough. Re-running the estimate more often than the source data changes adds work without improving the decision.

Setting the check inside the budget cycle is simpler with an affiliate marketing budget template that keeps assumptions next to the numbers.

Disclosure rules and what you can count

The CAP Code's section 2 on the recognition of marketing communications, rule 2.1, requires marketing communications to be obviously identifiable as such. The ASA's advice on affiliate marketing treats a paid affiliate link as an ad that needs a clear label before the click.

Disclosure changes what you can count. Labelled links leave a measurable trail you can attribute. Unlabelled links risk a ruling, so their traffic is a weak base for an estimate.

Registration and record keeping matter too, because your own commission records are the narrow measure. GOV.UK's Companies House register statistics give the number of companies on the register, which is the advertiser base any England estimate is built on.

Common questions

Is there an official England affiliate market size?

No. The nearest official series is the ONS monthly retail sales bulletin for Great Britain, which excludes commission payments. Build your own figure and label it as self-built.

Which source should I use first?

Start with the ONS monthly retail sales bulletin for demand context, then your Awin, CJ Affiliate or Impact statements for payouts, then your own commission records for the measure you can defend.

How often should I refresh the figure?

Refresh when a trigger fires: a new ONS release, a contract renewal, or a change in your commission rates. One annual review covers most planning cycles.

Can I quote one number for England?

Only with the definition, period, sources and adjustments stated. A bare number cannot be compared with anyone else's.