A marketing agency needs no licence and almost no money to start — a laptop, some software and a client. What it needs to survive is a particular shape: a service you are genuinely good at, sold to a type of business you understand, on a monthly fee rather than one job at a time. Agencies that get that shape right have steady income and can plan; agencies that take any work from anyone lurch from project to project. This guide is about building the first kind. It is part of our guide to starting a business.
At a glance
| Feature | Detail |
|---|---|
| Qualifications | None required; clients buy proof of results, not certificates |
| Startup costs | Low — laptop, software subscriptions, insurance, a simple website |
| How you get paid | Monthly retainer, fixed-price project, or a share of results |
| What makes it stable | Retainers — income that arrives whether or not you sold anything this month |
| The margin killer | Scope creep, and hours given away for free |
| The risk to watch | One client making up a large share of your income |
Pick a service and a sector
The instinct when you start is to say yes to everything, because saying no to money feels mad. It is also the fastest way to be mediocre at six things.
Pick one service you can do better than most people: paid search, paid social, search optimisation, email, content, or websites. Then pick one type of client: dentists, estate agents, builders' merchants, recruiters, independent gyms. The combination is what makes you easy to recommend and easy to buy.
There are three practical reasons this works. You get faster, because the fourth estate agent's account looks a lot like the third. You get better results, because you already know what works in that sector. And your marketing writes itself, because "I run Google Ads for independent estate agents" gets repeated in the exact meeting where someone needs it, while "we do digital marketing" does not. You can widen later.
Pricing: retainer, project or performance
How you charge decides what kind of business you have, so this is worth getting right before your first proposal.
Project pricing. A fixed price for a defined piece of work — a website, a campaign build, an audit. Good for starting a relationship and easy for a nervous client to say yes to. The problem is that every month begins at zero: finish the project, and you have to sell another one.
Retainers. A fixed monthly fee for an agreed amount of ongoing work. This is what makes an agency stable. You know what is coming in, so you can commit to costs like software and salaries. Your clients get someone who knows their business rather than a stranger every quarter. And you get paid for the boring months as well as the exciting ones, which is when the results actually compound. Even three or four solid retainers change the whole feel of running the business.
Performance pricing. A share of the sales or leads you generate. It sounds fair and clients love the idea, but it puts your income at the mercy of things you do not control — their prices, their sales team, their stock. Use it as a bonus on top of a retainer, not instead of one.
The most common mistake is pricing from what you think a client will pay rather than from what the work costs you in hours. Work out how many hours a month a retainer really takes, including the calls and the reporting, decide what your hour needs to be worth, and price from there.
Work out your pricing with Plan, free. Plan does the pricing maths with you — costs, margin and what to charge — one short question at a time, in your browser. Our pricing guide covers the method in full.
Scoping, and the creep that eats the margin
Scope creep is what happens when a £1,200 retainer quietly starts including a newsletter, some social posts and "just a quick landing page". Nobody plans it. It arrives one small favour at a time, and by month six you are doing twice the work for the same money and wondering why the business feels hard.
Three things stop it, and none of them require being difficult.
Write down what is included, in specifics. Not "social media management" but "twelve posts a month across two channels, one monthly report, one call". Numbers make the boundary visible to both of you.
Have a change note, and use it cheerfully. "Happy to do that — it is outside the retainer, so I will send you a quick quote." Said early and pleasantly, that is a normal business conversation. Said for the first time in month nine, it feels like a complaint.
Track your hours per client, even roughly. It is the only way to notice that your best-paying client is now your worst-paying one per hour. Review every retainer twice a year against what it actually takes, and raise the ones that have drifted.
Freelancers first, staff later
You will hit a ceiling — the point where you cannot take another client without dropping a ball. The instinct is to hire. Usually the right first move is a freelancer, because freelancers flex with your workload, cost nothing in the quiet months, and let you test whether the extra work is really there before you commit to a salary. Build a small bench of two or three you trust and use them often enough that they answer the phone.
Hire an employee when three things are true at once: the work is steady rather than a good quarter, you could cover that person's full cost for several months even if a client left, and the job is genuinely a job rather than a pile of tasks you have not systemised yet. Remember that a salary is not the cost of a person: employer National Insurance and pension add roughly 15% on top, plus a laptop, software seats, holiday and the time you spend managing them.
Client concentration: the risk worth naming
One client at 60% of your income is not a comfortable business. If they leave — and clients leave for reasons that have nothing to do with you, like a new marketing director or a bad quarter — you lose more than half your income in one email, and you cannot cut your costs anything like that fast.
So watch the share, not just the total. A useful working target is that no single client should be more than about a quarter of your income. If one is, the answer is not to sack them: it is to keep selling while you are busy, because most small agencies stop marketing themselves the moment they have enough work, which is precisely how concentration builds. Where a large client is unavoidable, protect yourself with a longer notice period and a cash buffer covering their share of your costs for a few months.
Contracts, notice and getting paid
Get one contract drafted properly and reuse it. The clauses that matter for an agency:
- What is included, in specifics, and what is not.
- Notice period. Thirty days is common and leaves you exposed; a three-month notice period on a retainer is not unreasonable and gives you time to replace the income.
- When you invoice. Bill monthly in advance, not in arrears. You are committing your time to that month; get paid for it at the start of it.
- Who owns what — accounts, ad accounts, creative work — when the relationship ends. Set client ad accounts up in the client's own name from day one. It avoids an ugly conversation later and it is the professional thing to do.
- Late payment. Say what happens, including pausing work, and be willing to use it.
Professional indemnity insurance matters here too, because your product is advice and work that clients rely on. Our insurance guide covers what agencies typically carry.
The arithmetic of a small agency
Take Owen, starting an agency in Norwich that runs Google Ads for independent estate agents. These are his numbers, for the example — build yours from your own costs and market.
Owen charges a retainer of £1,200 a month. Six clients gives him £7,200 a month of sales — sales, which is money coming in, and the word HMRC uses for it is turnover. His costs are modest: reporting and campaign tools, an accountant, insurance, phone and broadband, some stock imagery and travel to clients. Call it £700 a month. That leaves about £6,500 a month before tax.
Two honest notes on that. Getting to six retainer clients takes most people a year or more, so the first months look nothing like this. And six clients at that fee is roughly a 45-hour week once the calls, reporting and his own marketing are counted.
The team version works differently. Owen hires an account executive on £30,000. With employer National Insurance and pension that is around £34,000 a year, or about £2,830 a month, plus their software seats and laptop. That person can carry the delivery work for perhaps five clients, and they need to be attached to enough client income to cover their full cost several times over, because their hours also fund the management, the selling and the months when a client leaves.
So the question is not "can I afford £2,830 a month?". It is "do I have, or can I win within a quarter, the five or six extra clients that make that person pay?". Chargeable hours across a team, not just your own, is what an agency's numbers are really made of.
Getting your first clients
Almost every agency's first client is somebody who already trusts the founder: a former employer, a former colleague who has moved on, or a business you have quietly helped before. Tell those people specifically what you now do, and ask directly.
After that, this trade is one of the few where our usual advice about Facebook and Instagram does not apply — your buyers are business owners and marketing managers, and LinkedIn is where they are. Post what you actually know, plainly, once a week, showing the working from real campaigns with permission and numbers where you can. One consistent useful post a week beats a burst of activity followed by silence.
Two more work early: local business networks, where the person who runs the estate agency is genuinely in the room, and doing one piece of work at a reduced rate in exchange for a case study and a reference, agreed openly. Our guide to marketing a small business covers the groundwork — and running your own marketing well is the best advert you have.
The admin
Many agencies trade as limited companies, partly because larger clients prefer contracting with a company and partly because it separates the business from your personal finances. Starting as a sole trader is simpler and perfectly fine while it is just you; our structures guide covers when to change. If you form a company, issue 100 shares rather than one — it costs nothing extra and makes bringing in a partner or selling a stake far easier later.
Watch the VAT registration threshold of £90,000 of sales, because six retainers can carry you past it faster than you expect. And if you handle client customer data — email lists, ad audiences, form enquiries — you have data protection duties of your own; our GDPR and ICO guide explains them in plain English.
Turning this into a plan
An agency plan comes down to five numbers: your retainer price, how many clients you can serve well, your monthly costs, the cost of the first person you hire, and how long a new client takes to win. Put those together and the useful questions answer themselves — how many retainers cover your own wage, at what point a hire pays for itself, and how much income a single client leaving would actually take with them.
Create a mini business plan in minutes with Plan.business. Put in your rate, your hours and your costs, and it works out the rest — what you will make, when you break even, and what you need to charge to hit your target.
Frequently asked questions
How much should a marketing agency charge for a retainer? Build it from hours, not from what feels sellable. Work out how many hours a month the work genuinely takes, including calls and reporting, decide what your hour needs to be worth to cover your costs and your own wage, and price from there. Ranges vary widely by service and sector, so use them as a sense-check rather than a source.
Is a retainer better than project work? For stability, yes. A retainer means income arrives whether or not you sold anything this month, which lets you commit to costs and plan. Project work is a good way to start a relationship and often leads to a retainer, but an agency living on projects starts every month at zero and spends much of it selling.
How many clients can one person handle? It depends entirely on the service, but most solo agency owners find the ceiling somewhere around five to eight retainer clients before quality slips. Track your hours per client to find your own number, and use freelancers to stretch it before you commit to a salary.
Do I need qualifications to start a marketing agency? No. There is no licence and no required qualification in the UK. Clients buy evidence that you have done this before for a business like theirs, so results, references and case studies are your qualification. Platform certifications are quick to get and worth having, but they win very few clients on their own.
What insurance does a marketing agency need? Professional indemnity is the main one, because your product is advice and work clients rely on, and larger clients often specify a minimum level before signing. Public liability is cheap to add if you visit client premises, and employers' liability is a legal requirement once you take on staff.
Figures correct as of September 2026. Tax thresholds, fees and rates change; check the linked GOV.UK pages before acting. Prices and costs shown are indicative and vary by area and by what's included.
What is Plan?
Plan is a free business operating system for people starting or newly running a UK business. It walks you, one simple step at a time, from your elevator pitch through brand, product and pricing, to a complete business plan — then uses everything it now knows about the business to help with the basics: logo and brand, marketing, a website, a bank account, funding, insurance, company registration. You can use as much or as little as you want.
Two ways to do this
Do it yourself, free. Plan walks you through the agency numbers — your retainer price, how many clients you can carry, your costs, and what a first hire really costs — one short question at a time, in your browser. Do just this bit and stop there if that is all you need.
Or just do the pricing bit. If the only question keeping you awake is what to charge for a retainer, you do not need the whole plan. Plan's pricing section works out costs, margin and your price on its own, in about ten minutes, and you can leave the rest for another day.