Guide / Agency vs in-house

Marketing agency vs in-house team — which should I hire?

Below £5M revenue, agency usually wins on cost. Above £5M with marketing as a core driver, in-house often wins. Below is the honest cost, capability, and scaling comparison. — Oliver Ball.

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The short answer

Agency wins below £5M revenue. You get senior multi-channel capability without the £200k+ all-in cost of building a small in-house team.

In-house wins above £5M revenue with marketing as a core revenue driver. You get always-on capability, deep brand knowledge, and operational integration that agencies can’t match.

Hybrid wins for many. Internal marketing manager + agency partner is the most common growth model.

In-house cost reality (UK)

A bare-minimum in-house marketing function for an SME:

  • Marketing manager: £35-£60k salary + 25% on-cost = £45-£75k all-in
  • Paid media specialist (or agency-as-partner): £40-£70k salary + on-cost = £50-£90k
  • SEO specialist: £30-£55k salary + on-cost = £40-£70k
  • Designer: £35-£60k salary + on-cost = £45-£75k
  • Content writer: £30-£45k salary + on-cost = £40-£60k
  • Tools (Ahrefs, SEMrush, Klaviyo, Adobe, etc): £8-£25k/year
  • Recruitment / training / management overhead: 10-20% of salaries

All-in for a small full-stack in-house team: £200-£350k/year. Equivalent agency capability: £20-£60k/year (£1,500-£5,000/month).

Where agencies genuinely win

  • Multi-channel breadth. One retainer covers SEO, ads, web, content. Building this in-house requires 4+ hires.
  • Senior expertise on day one. No 3-month onboarding curve. Senior operators bring frameworks immediately.
  • No employment overhead. No PAYE, NI, pension, holidays, performance management, recruitment costs.
  • Cross-client learning. Agencies see what works across many businesses. In-house sees only their own data.
  • Flexibility. Scale spend up or down with 7 days’ notice (in our model). Hiring and firing employees is much harder.
  • No single-point-of-failure. One employee leaving can leave a marketing function blind. Agencies have continuity.

Where in-house genuinely wins

  • Always-on availability. Internal team available all day, every day. Agencies have working hours.
  • Deep brand knowledge. An in-house marketer knows the product, customers, and operations intimately after 12 months.
  • Operational integration. In-house people sit in operations meetings, sales reviews, product planning. Agencies are external.
  • Custom systems and workflows. Building bespoke systems internally is faster than negotiating them with an agency.
  • Cost at scale. Above £5M revenue with multi-channel marketing as a primary revenue driver, in-house economics catch up to agency economics.
  • IP retention. Strategy, audience research, creative IP stays inside the company permanently.

The hybrid model — usually optimal for £1M-£10M revenue

Most £1M-£10M businesses run a hybrid:

  • Internal: Marketing manager + content writer. £80-£120k all-in.
  • Agency: SEO + paid media specialist capability. £20-£60k/year.
  • Total cost: £100-£180k/year. Capability matches a £200-£300k pure in-house team.

The internal team handles strategy, brand, and operational integration. The agency handles execution where senior specialists are most needed (technical SEO, paid media architecture, conversion tracking, complex campaigns).

Failure modes — where each model breaks

Agency failures:

  • Account manager model — pitch team isn’t delivery team
  • Junior staff doing senior work
  • Reports designed to obscure rather than inform
  • 12-month contracts trapping clients in bad work
  • Generic templates instead of custom strategy

Mitigated by hiring agencies with founder-led delivery, rolling monthly contracts, and direct operator access. Why most SEO agencies don’t work.

In-house failures:

  • Hiring one person to “do all the marketing” who burns out trying
  • Generalist hire who lacks specialist expertise
  • No cross-pollination from other businesses or industries
  • Single-point-of-failure when person leaves
  • Recruitment costs and time eaten by hiring process

A simple revenue-tier framework

  • Sub-£500k revenue: Agency, freelancer, or DIY. In-house is too expensive.
  • £500k-£2M revenue: Agency-led, with founder or marketing-curious operations person internally.
  • £2M-£10M revenue: Hybrid — internal marketing manager + agency for specialist execution.
  • £10M-£50M revenue: Strong internal team (3-6 people) + agency for specialist work or campaign capacity.
  • £50M+ revenue: Mostly in-house, occasional agency partnership for specialist projects.

FAQs

Can I hire just a marketing manager and skip the rest?

For some businesses yes, but expect breadth-over-depth. A marketing manager can handle some SEO, some ads, some content — none expertly.

What’s the cheapest way to start marketing?

Agency at £400-£1,000/month or freelancer at similar. Pricing here.

Can I switch from agency to in-house later?

Yes — common growth path. We’ve helped clients transition by handing over assets, audiences, and frameworks.

Will agencies share their playbooks with my in-house team?

Reasonable agencies yes. We share frameworks freely. More on our approach.

What if I want both immediately?

Hybrid from day one is fine. Marketing manager + agency works at any revenue level.

Do you work alongside in-house teams?

Yes — most of our clients have at least one internal marketing person. We complement, not replace.

Should I outsource everything?

Below £500k revenue, possibly. Above that, having at least one internal person is usually worth it.

What does Signal Marketing recommend?

Depends on your stage. Send us your numbers and we’ll come back honest. Alternatives page.

“These guys are the real deal. Have helped grow our revenue massively over Q4.”

— Built Different, verified Trustpilot review

If an agency is the right call

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Send your stage and revenue and we’ll come back with an honest agency-vs-in-house recommendation.

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