How to move a client onto a monthly retainer

Some clients are already on a retainer

They send work every few weeks. You scope it, quote it, do it, invoice it, and a fortnight later the same thing happens again with a different brief. Neither of you has called it an arrangement, but that is what it is. You are carrying the cost of quoting it over and over, and the client is carrying the risk that one month you'll be booked up.

That client is the one to ask. You are not proposing a new relationship, you're proposing to stop re-negotiating the one you already have. It's a much easier conversation than selling a retainer to someone who has never hired you.

What a retainer actually buys

There are two versions, and mixing them up is where most retainers go wrong.

A capacity retainer sells reserved time. The client pays a fixed monthly fee for an agreed block, say four days a month, and gets first call on it. If they don't use it, they still pay. What they're buying is certainty that you'll be there.

A deliverables retainer sells a defined output every month. Four blog posts, one campaign, a monthly report, whatever the work is. The client pays for the thing, not the time it takes.

Capacity retainers are simpler to defend when a month goes quiet, because the client bought availability and got it. Deliverables retainers are easier to sell, because the client can see what they're getting. Pick one and write it down. The dangerous version is the unnamed hybrid where the client thinks they've bought a fixed output and you think you've sold a fixed number of hours.

Pricing it, and what the reduction is for

Most retainers come in a little under the equivalent ad-hoc rate. That reduction is not a loyalty gift. It's payment for something real: guaranteed income, no repeat pitching, no gap between jobs, and one invoice a month instead of five.

Work it out from your own numbers rather than a rule of thumb you found online. Take the hours or deliverables you're committing to, price them at your normal rate, then decide what the certainty is worth to you. If you can't name a figure you'd be content to receive in a month where the client barely calls, the price is wrong.

Two things to keep an eye on. Set a review date, usually every six or twelve months, so the price isn't frozen at the moment you were least confident. And check that the retainer isn't quietly your worst-paid work: if the client consistently uses more than the agreed block, the effective rate has dropped and you're subsidising them.

What has to be in writing

A retainer without a written scope becomes unlimited work for a fixed fee, and it happens gradually enough that you won't notice until you resent it. The agreement needs to cover:

• The cap. Hours, days or deliverables per month, stated as a number.
• What happens to unused time. Usually it expires. If you let it roll over, say how far, or you'll end up owing a client eleven days in December.
• Overflow. What you charge for work beyond the cap, and whether it needs approving first.
• Notice. Thirty days on both sides is common. This is the clause that stops a retainer ending by text message.
• Payment terms and the billing date. Retainers are normally invoiced in advance, at the start of the period the client is buying.
• The review date. A fixed point where the price and the scope get looked at again.

If you already have a contract with this client, a short amendment referring to the original terms is usually enough. You don't need to start again.

The one-client problem

A retainer that grows into most of your income starts to look, from the outside, like a job. That matters for tax. HMRC's employment status guidance says someone is probably self-employed if they quote for work, aren't under direct supervision, submit invoices, pay their own tax and National Insurance, and don't get holiday or sick pay. A monthly fee doesn't break any of that on its own. Working set hours, at their desk, under their direction, with no ability to send anyone else, might.

If you're unsure, HMRC's Check Employment Status for Tax tool is free and anyone can use it, including you rather than the client. HMRC says it will stand by the result as long as the information you gave was accurate and the working arrangement doesn't then change. Keep a copy of the answers you gave with the contract.

The commercial version of the same risk is simpler. A client who is a large share of your income can set your terms, and losing them takes most of your business with them. A retainer makes that dependence comfortable, which is exactly what makes it easy to miss.

Getting the money in

The retainer invoice is a commercial invoice like any other, so the late payment rules apply to it in full. Where you've agreed terms, those terms stand. Where you haven't, gov.uk says payment is late 30 days after the client gets the invoice, or 30 days after you deliver the work, and terms longer than 60 days between businesses have to be fair to both. If it goes past due you can add statutory interest at 8% over the Bank of England base rate plus a fixed sum by invoice size, and gov.uk lists the amounts.

Practically, the thing that kills retainers is not the client, it's you forgetting to raise the invoice in a busy week. Bill on the same date every month, before the work rather than after it, and set it up once so it doesn't depend on you remembering.

The bottom line

Retainers are worth having because they turn a pipeline you have to keep refilling into income you can plan around. They're only worth having on terms you'd still accept in a quiet month, and with a scope you can point at when the requests start creeping. They stop being worth it the moment one client is big enough that you couldn't walk away.

Start with the client who is already behaving like a retainer client, and write down what both of you have been assuming.