Outsource Marketing vs In-House: What the Data Actually Shows

The debate around outsource marketing vs in-house keeps circling the same assumptions: that building internally gives you more control, faster output, and better value. The ISBA's research into in-housing tells a different story. Among senior marketers who brought capabilities in-house, 93% expected cost-effectiveness. Only around 60% experienced it. The speed gap was even wider, with 93% expecting faster delivery but just 40% reporting it. As ISBA put it, "the majority of senior marketers admitted the reality didn't match the expectations".

For UK B2B company leaders weighing this decision in 2026, the question is no longer theoretical. Rising employer costs, persistent skills shortages, and flat marketing budgets have changed the calculus. Here is what the evidence actually supports.

The expectations gap: what ISBA found

ISBA's study measured the gap between what companies expected from in-housing and what they got. The results were consistent across every metric.

Cost-effectiveness: 93% expected it, roughly 60% achieved it.

Speed: 93% expected greater speed, only 40% experienced it.

Control: The strongest argument for in-housing, yet only 53% of respondents said they achieved greater control.

Despite these results, 60% of brands said they planned to in-house more marketing functions. That disconnect between evidence and intention is worth noting. It suggests the decision is often driven by instinct rather than data, which is precisely why a structured comparison matters.

What a UK in-house marketing team actually costs

Salary data from 3Search and EMR for 2025 puts a Marketing Manager in the UK at £45,000 to £70,000 and a Head of Marketing at £70,000 to £125,000. Those figures are gross salary alone. The true cost of employment sits at 1.2 to 1.4 times the gross figure once you factor in National Insurance, pension contributions, benefits, and recruitment costs.

Since April 2025, employer costs have increased further. Employer National Insurance rose from 13.8% to 15%, and the threshold dropped from £9,100 to £5,000, adding £800 to £1,200 per employee per year according to UK Government figures. For a marketing team of three or four people, that adds up.

A minimum viable in-house marketing function, one strategist and two specialists, costs upward of £200,000 annually before you account for software licences, training, or management overhead. And that team still has gaps. CIM and Hays found that 88% of UK marketing employers experienced skills shortages, with 52% specifically lacking AI capabilities. Hiring does not solve the breadth problem.

Why budgets are forcing the question

Marketing budgets have flatlined. Gartner's 2024 CMO Spend Survey recorded marketing budgets at 7.7% of company revenue, with 39% of CMOs cutting both agency and labour costs simultaneously. The IPA Bellwether Report for Q4 2025 confirmed the trend in the UK, with budget growth sitting at a net balance of 0.0% and only 1.7% of companies predicting an increase for the 2026/27 financial year.

Flat budgets and rising costs create a structural problem. You need marketing to generate pipeline and revenue, but the cost of delivering it internally keeps climbing. Deloitte's Global CMO Survey showed full-time employees now account for 77.9% of marketing hires, down from 82.5% in 2019. Companies are already shifting toward more flexible models, even if they have not labelled it as outsourcing.

The outsourced marketing model: what has changed

Traditional outsourced marketing meant handing a brief to an agency and waiting for deliverables. That model still exists, and it still underperforms for companies that need marketing integrated with their commercial strategy.

The embedded model works differently. As Monks (formerly MediaMonks) described it, "an embedded mindset offers the best of both worlds... teams are involved in strategic conversations much further upstream". An outsourced marketing department that operates this way functions as your marketing team, attending internal meetings, accessing pipeline data, and adjusting priorities based on commercial reality rather than a quarterly scope document.

The cost comparison is stark. A comprehensive outsourced marketing retainer delivering strategy, content, SEO, digital, and PR ranges from £36,000 to £96,000 per year. That is roughly a third to a half of what the equivalent in-house build costs, with tools, senior expertise, and production capacity included.

When in-house is the right call

Honesty matters here. In-house marketing is the better choice in specific circumstances.

Deep technical product knowledge: If your product requires months of immersion to understand and articulate, a dedicated in-house marketer who lives inside the business will outperform an external team on that dimension.

High-volume sales enablement: Companies with large sales teams generating constant requests for collateral, battle cards, and pitch support often need someone sitting alongside those teams daily.

Regulatory environments: Sectors with complex compliance requirements, such as financial services or healthcare, sometimes need marketing people who are embedded in the approval process full-time.

Even in these cases, most companies benefit from pairing a lean internal resource with an outsourced marketing team that provides strategic leadership and specialist execution. The hybrid approach is growing for good reason.

How to make the decision with data, not instinct

Before committing to either model, run the numbers for your specific situation.

Calculate true employment cost. Take the gross salary for each role you are considering, multiply by 1.3, and add recruitment fees (typically 15 to 25% of salary), software costs, and management time. Compare that figure against outsourced retainer proposals for equivalent scope.

Audit your skills gaps. List every marketing discipline your business needs over the next 12 months: strategy, content, SEO, paid media, PR, design, marketing automation, analytics. Count how many require specialist expertise. If the answer is more than three, a single hire or small team will leave gaps. CIM warned that marketing's digital skills gap could become "unmanageable" without intervention.

Measure ramp-up cost. An in-house hire takes 3 to 6 months to recruit and another 3 to 6 months to reach full productivity. That is up to a year of salary cost before meaningful output. An outsourced team with B2B experience can deliver within weeks.

Define what you are optimising for. If your primary goal is cost-efficiency and breadth of capability, outsourcing wins on the data. If your primary goal is deep product immersion and you have the budget to support a full team, in-house may be justified.

Outsource marketing vs in-house: the bottom line

The data does not support a blanket case for either model. It does show that in-housing consistently underdelivers on its promises for the majority of companies that attempt it, particularly on speed and cost. For UK B2B companies operating with flat budgets and rising employer costs, the embedded outsourced model offers broader capability at lower cost, with faster time to impact.

The right structure depends on your stage, sector, and commercial priorities. If you want to compare the models using your actual numbers, book a consultation with the Forge Together team. We will map your current marketing spend against what an embedded function would look like, so you can make the decision based on evidence rather than assumption. You can also learn more about how we work and the companies we support.