B2B Lead Generation Agencies: What They Actually Cost a UK Service Business (And When Not to Hire One)

You've typed "b2b lead generation agencies" into Google at 11pm, scrolled through a list of the "top 9" agencies with five-star badges and stock photos of people pointing at laptops, and closed the tab none the wiser. Every site says "results-driven." None of them say what a result actually costs.

A B2B lead generation agency for a UK service business doing £1m to £5m typically costs between £2,000 and £6,000 a month, plus the ad spend or outbound tools on top. The number that actually matters isn't the fee. It's whether the agency can show you cost per qualified lead, not just cost per lead, and whether those leads convert into paying work.

We've built and run lead generation systems for owner-led UK service businesses for over ten years. Here's what a B2B lead generation agency actually does, what it should cost you, and the six questions that separate a real one from a list-seller with a nice website.

What a B2B lead generation agency actually does

Strip away the jargon and B2B lead generation is one job: get your sales team in front of people who can say yes, and can afford to. How that happens varies.

Outbound agencies run cold email and LinkedIn outreach on your behalf, usually from a domain built specifically to protect your own, targeting a list built against your ideal customer profile. Inbound-led agencies run paid search and paid social to capture demand that already exists, then route it through forms and landing pages. Appointment-setting agencies do both, but they're paid specifically for booked meetings with a qualifying call in between, not raw form-fills. Most agencies worth hiring blend at least two of these, because relying on outbound alone or inbound alone leaves half the market untouched.

What none of that tells you is whether the leads are any good. That's the part every glossy homepage skips.

MQL versus SQL: the distinction that decides whether you get value

A marketing qualified lead is someone who fits your target profile and showed interest, downloaded something, filled a form, clicked an ad. A sales qualified lead is someone your sales team has actually spoken to and confirmed has budget, authority and a real need. Agencies selling on volume report MQLs. Agencies worth paying report SQLs, because that's the number that turns into revenue.

If an agency's pricing page only ever talks about "leads delivered" with no distinction between the two, assume they mean MQLs, and price it accordingly in your head.

What B2B lead generation costs a UK service business

Three pricing models dominate the UK market, and each one tells you something about how the agency is incentivised.

• Pay-per-lead: typically £50 to £150 per lead for mid-market B2B services, rising well past £200 for specialist or high-ticket sectors. Cheap on paper. The incentive is volume, not quality, unless the contract defines exactly what a "lead" is.
• Monthly retainer: UK B2B lead generation agencies running outbound, inbound or both typically charge £2,000 to £6,000 a month for a service business in the £1m to £5m range. Ad spend or outbound tooling sits on top, separately, so you can see exactly what went where.
• Pay-per-appointment: £150 to £350 per qualified sales meeting booked, often layered on top of a smaller base retainer. Aligns incentives well, because the agency only gets paid when your sales team actually gets a conversation.

Our own done-for-you marketing packages for UK service businesses run from £2,300 to £6,250 a month, covering paid acquisition, landing pages, follow-up and full attribution, not lead generation sold in isolation. Where a business lands in that range depends on how much of the system needs building and how far tracking needs to go, from cost per lead through to cost per closed deal.

In-house SDR versus outsourced lead generation: the real numbers

Take Mark, a fictional but typical example. He runs a £2.2m commercial insurance brokerage in the West Midlands. Referrals and renewals have carried the business this far, but new commercial accounts have stalled, and he's deciding whether to hire a sales development rep or bring in an agency.

Mark's numbers if he hires an SDR

• Salary (junior B2B SDR, outside London): £27,000
• Employer National Insurance and pension: £3,700
• Recruitment fee (15% of salary): £4,050
• Sales tooling (CRM seat, LinkedIn Sales Navigator, data enrichment, dialler): £3,600 a year
• Laptop, phone, onboarding time: £2,000
• Total year-one cost: £40,350

Then the part that doesn't show up in a spreadsheet. A junior SDR typically needs eight to twelve weeks just to learn Mark's product, market and objections, before their pipeline is worth anything. Quota attainment for a brand new SDR in their first quarter is low almost everywhere, because prospecting is a specific skill that takes months to build, not a switch you flip on day one.

Mark's numbers if he outsources it

A UK B2B lead generation agency running outbound for a business Mark's size typically costs £2,500 to £4,000 a month, roughly £30,000 to £48,000 a year, with an established outbound domain, existing sequences, and a team that's already done the eight-to-twelve-week learning curve for other clients in adjacent sectors. Campaigns are usually live within two to three weeks, not a full quarter.

The two numbers aren't wildly different. What's different is time to first result, and what happens if it doesn't work out. An underperforming agency, you replace next month. An underperforming SDR, you've got a difficult conversation and another hiring cycle.

Where AI actually helps B2B lead generation, and where it doesn't

Every agency now claims some flavour of AI B2B lead generation, usually meaning AI-written outreach sequences or AI-driven list enrichment. Used properly, this is genuinely useful: it can personalise outbound at a volume a human team can't match, and flag intent signals, a prospect visiting your pricing page, changing jobs, hiring for a relevant role, that a manual process would miss entirely.

Used badly, it's how you end up with five people at the same company getting near-identical AI-written emails in the same week, and your domain's deliverability quietly dying as a result. Ask any agency leaning on AI outreach one direct question: how do you keep this from reading like it was written by a machine and sent to everyone. If they can't answer, the tool is running them, not the other way round.

Six questions to ask before you sign with a B2B lead generation agency

• What's your working definition of a qualified lead, MQL or SQL, and how do you verify it before it lands in my inbox?
• Are the leads exclusive to me, or sold to other agencies and competitors in my sector at the same time?
• Who owns the contact data, the sequences and the domain reputation if we part ways?
• Show me a cohort of leads from 90 days ago. How many turned into a real conversation, and how many became paying work?
• What happens if volume drops below the agreed number, a discount, or continued work until it's fixed?
• What's the realistic ramp time before I should judge this, and what happens in that window?

An agency that answers all six without reaching for a case study PDF is worth a conversation. One that can't is selling potential, not a system.

When outsourcing beats hiring, and when it doesn't

Below roughly £20m in turnover, outsourcing lead generation to a team that's already built the system almost always beats a solo in-house hire on cost, speed and coverage. We've covered the full in-house versus fractional maths elsewhere, and the same logic applies here, just with an SDR instead of a marketing manager on the other side of the comparison.

There's one condition that matters more than turnover, though. Lead generation on its own is only half a system. If leads land and nobody calls them back inside minutes, you've paid for pipeline that dies in your own inbox. We've written about exactly why speed to lead makes or breaks paid leads, and the same rule applies whether the lead came from an ad or an outbound sequence. Before you sign with any lead generation agency, make sure someone on your side can pick up the phone in under five minutes. If nobody can, fix that first. It's cheaper than any agency fee.

Where Codebreak fits

We build and run marketing systems for owner-led UK service businesses doing £750k to £5m, with over £45m of ad spend managed and over £400m of trackable client sales along the way. We don't sell lead generation as a bolt-on. It's built into the same system as your follow-up, your tracking and your reporting, because a lead with no fast response behind it isn't worth much to anyone.

If you're staring at the same tab Mark had open, weighing up a hire against an agency, book a free strategy call. We'll look at your numbers and tell you straight whether outsourcing, hiring, or a hybrid of the two makes sense for where you are. If it's the hire, we'll say so.