Editorial rules / 4 September 2026

How London product design agencies are rated

Agencies pass a UK relevance, product capability, and evidence gate before scoring. Five dimensions are scored from 0 to 10 in half-point steps. The arithmetic mean becomes the displayed score. Ties are resolved by comparable product evidence, audience fit, then recency. Payments and submissions cannot change a position.

Eligibility comes before scoring

An agency needs a London or UK delivery record relevant to product teams. A company without a London office may qualify when it has clear UK work and a practical delivery model.

The portfolio must include shipped product, service, or complex UX work. Every profile needs at least two accessible sources.

Source hierarchy

Detailed cases and working products carry the most weight. Official service pages can establish capability but cannot prove that capability was applied on a project.

Client publications, procurement records, and verified review profiles help corroborate scope, dates, and working quality. Vendor claims remain identified as vendor claims.

Calculation and tie breaks

The five dimensions carry equal weight. Editors use 0.5-point steps, calculate the arithmetic mean, and round once to one decimal place. There is no hidden adjustment after the average.

A tie is resolved first by directly comparable product evidence, then fit for London buyers, then the recency of the strongest relevant work.

Updates and corrections

The date moves only after a substantive evidence review. An agency can submit a correction or new source, but submission does not guarantee inclusion or a score change.

Send the exact disputed statement, the source URL, and the date checked to inquiry@londondesignindex.com.

What the score means

The score is an editorial assessment for this audience. It is not a customer-review average, award, certification, or guarantee of project performance.

The publication is an AI Ratings editorial project. Positions are not sold. Agency selection and evidence scoring require editorial judgment.

Anchored rubric

London and UK delivery evidence

Recent work for London or UK organisations with enough context to judge delivery.

0No UK presence and no verifiable UK delivery.
5A UK office or isolated UK project with limited detail.
10Several recent UK engagements with named scope, users, and working context.

Product design depth

Work across discovery, interaction, interface, systems, and release rather than marketing pages alone.

0No product-design evidence.
5Competent interface work with a narrow process record.
10Repeated end-to-end digital product work with decisions traced from problem to release.

SaaS, AI, and complex-software fit

Evidence for dense workflows, data, permissions, AI behaviour, and operational products.

0Only simple content or campaign work.
5Some software clients but little complex-workflow evidence.
10Repeated SaaS, AI, or enterprise products with states, data, and operational constraints.

Research and accessibility

User research, testing, inclusive practice, and evidence that findings changed the design.

0No visible research or accessibility practice.
5Research is named but decisions are difficult to trace.
10Repeated studies, testing, accessibility evidence, and clear research-to-design decisions.

Shipped work and source quality

Detailed cases, live products, dates, and corroboration outside an agency portfolio.

0Unverifiable or concept-only claims.
5Named work with limited supporting detail.
10Several shipped products, detailed cases, recent dates, and credible outside confirmation.

Return to the ten-agency ranking