How to run a reference check on an SEO agency

Why the offered reference tells you almost nothing

Every buying guide says "ask for references". Almost none says what happens next: the agency picks the happiest client on the roster, calls them first, tells them roughly what to expect, and hands you the number. Nothing about that is dishonest. It's selection, and you'd do the same.

So treat the offered call as a low-yield formality with one genuinely useful output. Whoever they nominate is their idea of a success story. If their best case is a 40% traffic rise with no mention of leads, you've learned what they optimise for — and you've learned it in four minutes.

• Reciprocal references are common. Two agencies who refer work to each other, a client who is also a supplier, a friend from a founder group. Ask directly: "do you have any commercial relationship with them beyond the retainer?" It's a fair question and the pause is informative.
• Testimonials on a site aren't references. They're quotes, sometimes years old, occasionally written by the agency and approved by email. A named person, a company, and a working phone number is a reference. A first name and a job title is decoration.
• Case studies aren't references either. They're written by the party with the incentive. Read why SEO case studies mislead before you weigh one heavily.
• Logos on the homepage prove a transaction, not a result. A ₹40,000 one-off audit two years ago earns a logo on most agency sites.

Finding the clients they didn't nominate

This is the part that takes an hour and changes the decision. You're looking for businesses that paid this agency and no longer do. Everything below uses public sources.

Work through it in order — the first two find most of what there is.

1. Pull their portfolio page out of the Wayback Machine. Open web.archive.org, enter the agency's clients or work page, and open a capture from two and three years ago. Compare it to today. The logos that disappeared are your list. Nobody removes a happy client from a portfolio.
2. Search for their footer credit as an exact phrase. Agencies leave lines like "SEO by [Agency]" or "Website by [Agency]" in client footers. Search the exact phrase in quotes, then repeat with site: on any domain you already suspect. Google documents both operators; the exact-phrase form is what makes this work.
3. Read their case study PDFs and decks. Search the agency's domain for filetype:pdf. Decks that were never meant to be indexed name clients the website doesn't.
4. Check LinkedIn tenure overlaps. Find the agency's account managers, look at who they worked with, then look at marketing managers at those companies whose own tenure ended around the same time. The person who ran the account client-side is often the most candid source you'll find, and they no longer work there.
5. Look at who they've published for. Guest posts, webinar co-hosts, joint press releases, conference panels. A co-branded webinar from 2023 with a brand absent from today's portfolio is a lead.
6. Check the linking footprint. If the agency's own site is linked from a set of client footers, that set is close to a client list — and it's also a problem, because Google explicitly names widely distributed links in the footers or templates of various sites as link spam. The footprint that helps you research them is the same footprint that puts their clients at risk.

The four-minute call that gets a real answer

Former clients will give you four minutes and will not give you forty. Cold-email or message the person directly, say you're evaluating the same agency, and ask for four minutes on the phone. The hit rate is better than you'd expect — people who had a bad experience are often keen to spare someone else one.

Three questions. Ask them in this order, and shut up after each one. The silence does more work than the question.

• Don't ask "would you recommend them?" It's a yes/no about social risk, not about the work, and almost everyone says yes to a stranger.
• Don't ask about price. You'll get a number without scope attached, and it'll anchor you wrongly. Compare proposals on scope instead.
• Do ask who did the work by name, then check whether that person still works there. An agency that was good in 2024 with a team that has since turned over entirely is a different agency wearing the same logo.

Reading the hedge

Most of the signal in a reference call is in phrasing, not content. People are reluctant to damage a supplier they may need again, so criticism arrives softened. Here's the usual translation.

One honest caveat before you over-read any of it. Some Indian agency contracts carry confidentiality or non-disparagement clauses, and some ex-clients are simply too busy. A short answer is sometimes just a short answer.

• "They were fine." Reliable delivery, no result worth naming. The most common answer you'll get, and the most useful one to hear early.
• "Great people." Volunteered before any comment on outcomes, this is a compliment about the relationship standing in for one about the work.
• A long pause, then "it depends what you need". They're deciding how much to tell you. Wait. Don't fill it.
• "We brought it in-house." Sometimes true and strategic, often the polite version of not renewing. Ask what the in-house person does differently now.
• "I can't really get into it." Information about the contract, not necessarily about the work. Ask instead whether they'd hire them again for the same brief — that's usually answerable.
• Instant, fluent enthusiasm with specific numbers ready. Either a genuinely great outcome or a briefed call. Ask them something the brief wouldn't have covered — what the reporting looked like in month nine, say.

Check the work, not only the story

A warm reference and a reverted site are entirely compatible. The client liked the team, the engagement ended, the next developer rebuilt the site, and none of the work survives. That's worth knowing before you buy the same thing.

Four checks on the ex-client's site, ten minutes each, no tools required.

1. Is the content still live? Take a page the agency claims and open it. Then open the same URL in the Wayback Machine from the engagement period. A page that was 1,800 words and is now 400, or is now a 404, tells you the client didn't value it enough to keep.
2. Is it still indexed? Search a distinctive sentence from the page in quotes. If nothing comes back, the page exists but Google isn't holding it — which is a different and more interesting problem.
3. Do the links still exist? If the agency published link placements, open two or three. Bought placements come down when someone stops paying for the hosting. Earned coverage stays up for years.
4. Did the site move? A migration after the engagement ended explains most disappearances honestly. Check the archived version of the old domain before concluding anything sinister.

How many references is enough, and when to stop

Three conversations is usually the whole exercise: the one they offered, and two you found. Add a fourth only if the first three disagree with each other.

You're not building a case. You're testing one specific claim — that this agency has done this kind of work, for this kind of business, and that something measurable happened. Once two independent people describe the same pattern, more calls stop adding information.

• Stop when the third call tells you nothing new. Consistency across sources is the signal. A fourth call rarely changes a decision.
• Weight by similarity, not by fame. An ex-client with your sales cycle and your budget is worth five enterprise logos in an unrelated sector.
• Zero findable ex-clients is itself a result. Either the agency is very new — fine, ask directly and price the risk — or the portfolio doesn't reflect the roster. Both change how you'd write the contract.
• Convert what you learn into contract terms. If two references say reporting went quiet after month six, put the reporting cadence and the named account lead in writing. What to put in an SEO contract covers the rest.
• Do this before you write the brief, not after. What you hear should change what you ask for — see how to write an SEO brief for agencies.