Social Media Marketing Agency vs In-House: What’s Better for UK Businesses in 2025?

Social media changes fast. Platforms evolve, consumer behaviour shifts and businesses are under more pressure than ever to show up online consistently - with content that actually converts.

So when it comes to managing your social media in 2025, most UK businesses face the same dilemma:

Should we hire an in-house social media manager, or partner with a social media marketing agency?

Both options work.
Both can deliver results.
But the choice you make depends heavily on your goals, your budget and how quickly you want to grow.

This guide breaks everything down in a clear, no-fluff comparison - using real data, industry insight and what we see every day working with small businesses, local Shropshire brands and UK marketing managers.

Let’s dive in. 👇

1️⃣ Why Social Media Matters More Than Ever in 2025

Social media isn’t just a brand awareness channel anymore. It’s the main discovery tool for UK consumers.

Here’s what the latest data tells us:

• 61% of UK consumers use social media as their primary method of discovering new brands
  (Source: Deloitte Digital, 2024)
• 78% of buyers have purchased something after seeing it on social media
  (GWI, 2024)
• Video drives up to 8x more engagement than static posts on Instagram and Facebook
  (Meta Benchmarking, 2024)
• 64% of small businesses say content consistency is their biggest challenge
  (Hootsuite, 2024)

This is why the right setup - in-house social media manager or agency - matters so much.
Your choice directly affects visibility, engagement, lead generation and long-term growth.

2️⃣ Hiring an In-House Social Media Manager (Pros & Cons)

An in-house hire works brilliantly for some businesses - especially those with daily content needs or heavy operational updates. But it comes with limitations too.

✨ Advantages of Hiring In-House

✔ They live and breathe your brand daily

They’re physically in your business. This makes it easier to capture spontaneous content, follow day-to-day activity and respond quickly to changes.

✔ Fast turnaround for reactive content

Need to film something today? Post an update now?
An in-house hire is available immediately.

✔ Great for content-heavy industries

Businesses like restaurants, gyms, retail stores or venues benefit from having someone on-site consistently.

❌ Disadvantages of Hiring In-House

✘ One person can’t cover every skill needed in 2025

Social media now requires:

• Strategy
• Videography
• Editing
• Copywriting
• Paid ads
• Analytics
• Trend awareness
• Community management

Expecting one employee to do all of this well isn't realistic.

✘ Hidden costs add up quickly

A mid-level social media manager in the UK earns:

• £30,000–£45,000 per year (Indeed, 2025)

Once you add:

• Employer NI
• Pension
• Software
• Equipment
• Training

Total annual cost easily reaches £40,000–£55,000+.

✘ Knowledge stagnation is common

Unless you invest heavily in training, they may fall behind trends, platform changes and best practices.

✘ Bandwidth is limited

Sickness, holidays and burnout = your social media stops.

3️⃣ Working With a Social Media Marketing Agency (Pros & Cons)

A social media agency offers breadth of expertise, scalability and stronger performance - but it’s not right for everyone. Here’s the real picture.

✨ Advantages of Hiring an Agency

✔ You get an entire team, not one person

A modern agency provides:

• Strategists
• Videographers
• Editors
• Designers
• Copywriters
• Paid Ads Specialists
• TikTok & Reels Experts
• Data Analysts

This instantly increases output, creativity and results.

✔ Better quality content

Agencies produce content built for today’s algorithms:

• High-quality Reels
• TikTok-style videos
• UGC content
• Trend-led creative
• Strong storytelling

This is content designed to win.

✔ More cost-effective than a full-time hire

Most agencies cost:

• £1,000–£2,000 per month for SMEs
• £2,000–£5,000+ for larger businesses or heavy content needs

This is often cheaper than hiring someone full-time - and you get far more expertise.

✔ Faster results and stronger strategy

Because agencies work across multiple industries and accounts, they know:

• What’s working
• What’s outdated
• What’s converting right now
• What type of creative wins across platforms

You skip the guessing stage.

✔ Scales with your business

Need more ads?
Need 20 videos in a month?
Need to move into TikTok Shop?
An agency adapts - instantly.

❌ Disadvantages of Hiring an Agency

✘ They’re not physically in your business every day

At Evolve My Media, we don’t operate at arm’s length. We integrate into your business just like an in-house hire would - understanding your brand, your customers, your tone and your day-to-day operations. The difference is you get a full team’s worth of skills working behind the scenes.

✘ Not all agencies are equal

Some produce basic posts with no strategy.
Some rely on templates.
Some don’t stay ahead of trends.

Choosing the right agency matters.

4️⃣ Cost Comparison: Agency vs In-House in 2025

In-House Social Media Manager Costs

• Salary: £30,000–£45,000
• Real cost after NI, pension, software & overhead: £40,000–£55,000+ per year

Social Media Agency Costs

• Typical SME packages: £1,000–£2,000/month
• Full strategic management with content + ads: £2,000–£5,000+/month

Result?
Most small to medium businesses spend less on an agency while receiving significantly more output and expertise.

5️⃣ What UK Businesses Really Need in 2025

Here’s the blunt truth:

Social media in 2025 requires more than consistency.
It requires:

• A strategy based on buyer psychology
• A mix of short-form video, UGC and brand-led content
• Paid advertising expertise
• Analytics that actually lead to decisions
• Regular testing and iteration
• Trend-led creative
• Platform-specific storytelling

An in-house hire can’t realistically deliver all of this alone.
An agency is built for it.

6️⃣ When an In-House Hire Is the Better Option

To keep this comparison fair:

Choose in-house if you:

• Have constant operational updates
• Run a venue with fast-moving activity
• Already have a marketing strategist in place
• Have the budget to build a full in-house team

7️⃣ When a Social Media Agency Is the Clear Winner

For most UK SMEs, an agency offers:

• Greater ROI
• Stronger creative
• More consistency
• More expertise
• Faster growth
• Immediate access to specialists
• A predictable monthly cost

If you want leads, sales and growth - not just maintenance - an agency is the smarter option.

At Evolve My Media, we work as an extension of your in-house team, not an outside agency watching from a distance. Regular check-ins mean your strategy never goes stale and your content always reflects what your audience cares about.

8️⃣ FAQs

Is it cheaper to hire an agency or an in-house social media manager?

For most businesses, hiring an agency is cheaper and provides higher output for the cost.

Do agencies create content or just schedule posts?

Modern agencies create strategy, content, Reels/TikTok videos, UGC, paid ads and reporting.

Can one in-house social media manager do everything?

No - social media now requires multiple skill sets that one person cannot cover effectively.

What is the average social media marketing cost in the UK?

Agencies typically cost £1,000–£3,000/month, while in-house hires cost £40k–£55k+ annually.

Is an agency suitable for small businesses?

Yes - agencies are often the most cost-effective option for SMEs needing consistent growth.

Final Thoughts: Which One Should You Choose?

Both in-house and agencies work.
But they work differently.

Here’s your quick takeaway:

👉 In-house = speed, consistency, brand familiarity
👉 Agency = expertise, scalability, content quality, results

If you’re exploring support with content creation, paid ads, strategy or full social media management, Evolve My Media would love to help.

‍