How to check an ecommerce SEO agency at Companies House and the ASA

What to take away

What you can and cannot verify about an ecommerce SEO agency before shortlisting

Before you shortlist, separate what public records prove from what they merely suggest. Companies House confirms the company exists, who runs it and whether it files on time. The ASA shows whether its advertising has attracted complaints or sanctions.

You cannot verify client results, contract fairness, staff expertise or data practices from these sources alone. Those need references, test tasks and contract scrutiny. Public records narrow the field; they do not rank it.

Start with the legal name, not the trading name. Many agencies trade under a brand that differs from the registered company. Search both. If the brand has no registered company behind it, treat that as a question, not proof of wrongdoing.

Use a simple split. Hard facts: registration number, incorporation date, filing deadlines, directors, charges. Soft signals: growth in staff numbers, changes of address, repeated name changes. Hard facts decide eligibility; soft signals decide priority.

If you want a wider pre-shortlist method, see how to check ecommerce SEO best providers before you shortlist. It covers evidence types beyond Companies House and the ASA.

Reading Companies House registration and filing history for a UK provider

Go to the Companies House register and search the exact legal name. Open the company overview. Note the company number, incorporation date, registered office and company type. A private limited company is the normal UK trading vehicle.

Check the filing history tab. You want accounts and confirmation statements filed on time. Late filing is not fatal, but a pattern of it suggests weak administration. For a marketing supplier handling your revenue, administration matters.

Look at the accounts. Small companies often file abridged or micro-entity accounts. That limits what you can see, but you can still check whether the company is dormant, whether it has net assets and whether it has any charges.

Read the confirmation statement. It confirms directors, shareholders and the registered office at a point in time. If the statement is overdue, ask why before you shortlist. An overdue statement is a public fact, not a rumour.

Use the Companies House provider search to compare several shortlisted agencies side by side. Record the company number for each. This becomes the spine of your due diligence file.

Checking named directors, accounts and confirmation statements

Open the people tab. List every director and person with significant control. Search each name on Companies House for other appointments. Multiple dissolved companies under one director deserve a question, not an accusation.

Check whether the person who pitches you is a director or an employee. Sales staff change; directors carry legal responsibility. If the pitch is led by someone with no public role, ask who signs the contract.

Read the accounts for signs of scale. Turnover is often hidden for small companies, but employee numbers, fixed assets and creditors can indicate whether the agency is a two-person operation or a larger firm.

Look for group structures. Some agencies sit under a holding company. The trading entity may be a subsidiary with few assets. That affects who you can pursue if things go wrong.

Compare the registered office with the address on the agency website. A registered office can be an accountant's address, which is normal. A website address that does not exist is not.

For a fuller picture of when to run these checks, see ecommerce SEO vendor due diligence. It explains timing for shortlists and contract stages.

Searching ASA rulings and the non-compliant online advertisers list

The Advertising Standards Authority publishes rulings on advertising complaints it has investigated. Search the rulings database for the agency name, its directors and its main trading names. Read any ruling in full, not just the headline.

A ruling tells you what claim was made, why it broke the codes and what the ASA required. One upheld ruling may be a one-off. A pattern across years or brands is a serious signal.

The ASA also publishes a list of non-compliant online advertisers for due diligence. This names advertisers that have not complied with ASA rulings, often in paid search and social ads. Check the list for the agency and for any brands it promotes.

Being on that list means the advertiser ignored a ruling. That is directly relevant if the agency will run your paid search, shopping or social campaigns. You carry the commercial risk of non-compliant ads.

Search variations: limited company name, trading name, founder surnames and any white-label brands. Agencies sometimes advertise under a product name rather than the company name.

Record the date you searched and the exact result. If nothing appears, write that down too. A clean search is evidence, but only for the date you ran it.

Matching ASA advertising codes to the claims an agency makes

The UK advertising codes are written by the Committee of Advertising Practice and enforced by the ASA. They apply to online advertising, including agency websites, case studies, paid search ads and social posts.

Comparative claims are held to a high standard. If an agency says it is the leading ecommerce SEO provider, the ASA expects evidence for that position. Unsupported superlatives are a recurring cause of upheld rulings.

Testimonials and case studies must be genuine and representative. If a case study shows a 300 per cent revenue rise, the agency should be able to show the baseline, the period and the client's permission.

Pricing claims need care too. A headline monthly fee that excludes ad spend, content or technical work can mislead. The codes require ads to be clear about significant conditions.

When you spot a claim that looks strong, ask the agency for the evidence behind it. Then check the codes yourself. If the agency cannot produce evidence, treat the claim as decoration.

Use the ASA advice for businesses to understand what the regulator expects from advertisers, including agencies acting for clients. It is written for the advertiser, which is often you.

ASA sanctions show what happens when rulings are ignored. They can include naming, paid search ads highlighting the breach and removal of ad space. That reputational cost can attach to your brand if you share campaigns.

For a comparison method that scores evidence before price, see ecommerce SEO supplier comparison. It pairs well with the ASA checks above.

Building an ecommerce SEO agency due diligence file with dates and links

Build one file per shortlisted agency. Keep it factual and dated. Every entry should have a source link and the date you checked it. This protects you if the agency's public record changes later.

Use a consistent structure so you can compare agencies quickly. A spreadsheet works. One row per agency, one column per check, plus a notes column for links.

Keep the file versioned. If a director resigns or a ruling appears mid-process, you want to see when you learned it. This also helps if a colleague joins the decision late.

For a template that scores these checks, see the ecommerce SEO selection checklist. It turns the file into a comparable score.

Red flags that should end a shortlist conversation early

Some findings are serious enough to stop the process. You do not need to prove bad intent. You need enough doubt to spend your budget elsewhere.

A single late filing is not a red flag. A cluster of late filings, a dormant company and unsupported promises is. Weigh the pattern, not one item.

If the agency refuses to discuss its company details, that is itself a finding. Legitimate UK agencies expect these checks. They should be able to answer within a day.

When you read reviews, apply the same scepticism. See how to read ecommerce SEO agency reviews without taking claims at face value. Reviews and public records together give a fuller picture.

Common questions