In-house SEO or an agency: what each really costs in time and results

In-house SEO makes sense when you have enough work to keep a small team busy all year and the budget to hire across several skills. For most small and mid-sized businesses, an agency gets results faster because you get a full team for less than the cost of one senior hire. Many growing companies end up with a mix of both.

The decision often gets framed as salary against agency fees. That misses most of the real cost, which sits in time, management and the skills you can’t hire in one person.

So here’s how the two compare once you count everything.

What in-house SEO really costs

The real cost of in-house SEO is the salary plus everything around it. Before you hire, add up:

• Salary, employer National Insurance, pension and benefits.
• Recruitment time or fees, which for specialist roles can take months.
• Tools. A serious SEO setup usually needs a crawler, a keyword and backlink platform and rank tracking.
• Training to keep up with Google updates and AI search.
• Your own time managing, reviewing and unblocking the work.

Then there’s the skills gap. SEO covers technical work, content, digital PR and analytics. One person is rarely strong at all four, so you either accept gaps or hire a second person.

What an agency really costs

An agency’s fee is easier to see, but it has hidden costs too.

• Time spent briefing the agency on your business, products and customers.
• Approval time for content and technical changes.
• Developer time to make the changes the agency recommends, unless they can do it for you.
• The risk of a poor fit, which can cost months before you notice.

A good agency reduces the first two quickly. A poor one never does, which is why an SEO audit in the first month is a useful test of how well they understand your site.

Side by side: cost, speed, skills and risk

Factor	In-house SEO	Agency
Cost	Salary, on-costs, tools and training	Monthly fee, tools usually included
Speed to start	Slow: hiring and onboarding take months	Fast: work can start within weeks
Range of skills	Limited to who you hire	Technical, content, PR and analytics in one team
Business knowledge	Deep, and grows over time	Has to be built through briefings
Risk	Knowledge leaves when the person does	Easier to change supplier if results stall
Focus	Full time on your site	Shared across clients
Accountability	Competes with other priorities and slips when internal projects take over	Contracted deliverables and monthly reporting, and the work isn’t pulled onto other projects

What each means for results

In-house teams usually win on content that needs deep product knowledge and on day-to-day fixes. Agencies usually win on technical work, link building and spotting patterns across many sites.

Speed matters more than people expect. SEO takes months to compound, so a team that starts in week two rather than month four gives you a real head start. For B2B companies with long sales cycles that gap is even bigger, as we explain in how long B2B SEO takes to bring in leads.

Accountability: who answers when SEO stalls

An agency is paid to deliver SEO and nothing else. There’s a contract, an agreed plan and a monthly report, so if results stall you know who to ask and what was promised.

In-house SEO rarely gets that protection. Your SEO person sits in the marketing team, so they get pulled onto the website relaunch, the product launch or the trade show. Each one feels more urgent than this month’s SEO work. The plan slips a week at a time, and because nobody outside the business is checking, it can be months before anyone notices.

An agency doesn’t get borrowed for internal projects. The work in the plan happens on schedule, whatever else is going on in your business. If it doesn’t, you can hold them to it, or replace them.

When a hybrid works best

A hybrid works well once you have one person in-house who owns SEO and an agency that brings the skills they don’t have. Common splits:

1. In-house content, agency technical. Your team writes, the agency handles technical SEO, site structure and audits.
2. In-house strategy, agency delivery. A marketing lead sets priorities and the agency does the work.
3. Agency first, in-house later. The agency builds the foundations and trains your team to take over parts of it.

The hybrid only works if roles are written down. Who signs off content? Who briefs developers? Who reports to the board? Agree that on day one.

Signs your current setup isn’t working

Whichever model you have now, these are the warning signs that it needs to change:

• Reports show activity, such as pages written or links built, but not enquiries or revenue.
• Technical fixes sit in a developer backlog for months.
• Your in-house person spends most of their week on other marketing tasks.
• Nobody can explain why traffic went up or down last quarter.
• AI tools such as ChatGPT and Google AI Overviews don’t mention you, and nobody is tracking it.

One or two of these is normal. Three or more usually means the setup, not the effort, is the problem. Changing from in-house to agency, or adding an agency alongside your team, is often quicker than trying to hire your way out of it.

How to decide

Ask yourself four questions:

1. Is there enough SEO work for at least one person full time, all year?
2. Can you hire and manage someone with the right mix of skills?
3. How quickly do you need results?
4. What happens if that person leaves?

If you answered no, slow, quickly and “we’d start again”, an agency is the safer route for now. B2B firms in particular often start with a specialist B2B SEO agency and bring parts of the work in-house as they grow.

If you’d like help working out which model fits your business, our free strategy session looks at your current visibility, your team and what a sensible setup looks like. You can also read more about how our SEO agency works with in-house teams. Book a free strategy session.

Related reading: our guides to what an SEO audit is and holistic SEO.

Common questions