In-house team vs ecommerce agency (2026)
In-house wins for the strategic leadership layer (Head of Growth, Head of Retention) and brand-critical work. A senior agency wins for specialist execution SEO, paid, CRO, dev where hiring one senior per discipline costs 6× more than partnering with a team that already runs them.
Strategic ownership, brand voice, product decisions, roadmap.
Specialist execution across SEO, paid, CRO, email and development.
Side-by-side
| Criterion | In-house team | Ecommerce agency |
|---|---|---|
| Cost per senior specialist | £70-£120k + benefits | £3-£10k/month fractional |
| Depth of expertise | One area, deep | Multiple areas, deep |
| Brand ownership | Full | Partnered |
| Ramp time | 3-6 months | 2-4 weeks |
| Loss when someone leaves | Total (3-6 months) | Minimal (team pod) |
| Alignment with business goals | Highest | Requires strong brief |
| Access to tooling | You pay for it all | Included |
- Full brand and IP ownership
- Deep product context over time
- Strategic decisions stay in-house
- Culture and voice control
- High fixed cost with no flexibility
- Recruitment risk and 3-6 month ramp
- Single point of failure per discipline
- Hard to keep pace with 4 platforms + 5 disciplines
- Multiple senior specialists for less than one hire
- Zero recruitment risk
- Access to cross-brand pattern recognition
- Faster to scale up or down
- Requires strong internal owner to brief and QA
- Less deep on brand nuance without time
- Contracts and dependency risk if partner is weak
You have (or want) a Head of Growth or Head of Retention driving strategy and brief quality is high internally.
You need best-in-class execution across 3+ disciplines without hiring 3+ seniors, or your in-house team is stretched.
The bottom line
The right structure is almost never one or the other it's a small senior in-house team owning strategy and brand, partnered with a senior agency handling specialist execution. That combination beats a large in-house team on cost, and beats agency-only on brand fidelity.
Below £5M/year, agency-heavy usually wins on unit economics. Above £15M/year, the calculus shifts back to in-house for the disciplines closest to the product.
Frequently asked questions
Should I hire a Head of Growth in-house or use an agency?
Hire the Head of Growth in-house that's the strategy and brief layer. Use an agency for the specialist execution the Head of Growth then orchestrates.
When does in-house become cheaper?
When you can fill 40+ hours a week of specialist work in a single discipline. Below that, fractional senior agency time is nearly always cheaper on outcomes.
How do I avoid getting a bad agency?
Interview the senior operators, not the sales team. Ask to see three anonymised MER graphs from real clients, and reference-check with a founder who left them.