Sixty days unpaid and four polite emails in, the outcome of this was mostly decided months ago — in the appointment you signed and the narrative you wrote on the invoice. Everything from here is just execution. But execution matters, because there is a version of chasing this money that gets you paid and keeps the client, and a version that gets you an ARB complaint and a counterclaim for negligence. The difference is almost entirely about notice: what you give, in what form, and how long before you act on it.
So here is the ladder. Then the thing to fix so you never climb it again.
Before you write anything, work out which one you've got, because the treatment is opposite.
Silence is a cash flow problem dressed as rudeness. The invoice is sitting in someone's inbox, or in an approvals queue, or the client has spent the money on the kitchen and is hoping you'll go away. Silence responds to escalation and deadlines. Pressure works.
Dispute is a liability problem dressed as a cash flow problem. The client says the fee doesn't match the scope, the hours are inflated, the drawings were late, the planning advice was wrong. Pressure makes a dispute worse — it hardens a vague grumble into a formal position, and a formal position about your work is the first step towards a claim. Disputes respond to itemisation and evidence, not deadlines.
The mistake that costs practices real money is treating a dispute like silence: firing off a stern, clause-quoting letter at a client who was about to say "actually I thought stage three included the kitchen layouts". You've now escalated a misunderstanding into a position.
So rung one is not a letter at all.
Rung One: Stop Sending Reminders and Pick Up the Phone
A fifth reminder email is not escalation. It's a habit. It teaches the client that nothing happens on day sixty that didn't happen on day thirty.
Call them. Not to ask for money — to ask a question you genuinely want answered: is there a problem with the invoice, or is this a timing issue? That single question sorts silence from dispute in about ninety seconds, and it does it before anything is in writing that either of you has to defend.
Then — and this is the bit people skip — write up the call the same day. Short email, no drama: "Thanks for the call. To confirm what we agreed: invoice 0142 will be paid by the 14th; invoice 0151 you'd like itemised against the stage 3 deliverables, which I'll send tomorrow." You've just created a dated record of what the client said, which is the only thing that will matter if this ends up in front of an adjudicator.
If they don't answer the phone and don't reply to that email either, you are no longer dealing with disorganisation. A client who ignores three contacts over two weeks has made a decision. In practice, that's the moment to stop being informal — continuing to send friendly nudges past that point reads, later, as you not taking your own terms seriously.
Rung Two: A Formal Notice, Not a Firmer Email
The second rung is a letter that does four specific jobs. Send it as a PDF attached to an email and by post if the sums are serious, and address it to whoever signed the appointment — not the project manager who's been fielding you.
It should state:
The debt, itemised. Invoice numbers, dates, amounts, the clause of the appointment each one was raised under, and the date each fell due.
That the sums are overdue and no notice disputing them has been received. If you're under a contract caught by the Housing Grants, Construction and Regeneration Act 1996, this matters more than it sounds — the Act's payment regime means that if the paying party hasn't issued a valid pay less notice, the notified sum is the sum due. A client who has said nothing for sixty days has usually destroyed their own ability to argue about the figure.
Interest. Under the Late Payment of Commercial Debts (Interest) Act 1998, business-to-business debts carry statutory interest at 8% above the Bank of England base rate, plus a fixed sum of £40, £70 or £100 depending on the size of the debt. Two caveats worth knowing: that Act does not apply to a consumer client, and if your appointment has its own interest clause, that clause usually governs instead. Say which you're relying on.
What happens next, with a date. Not "we may have to consider suspending". A date, and the consequence.
Keep the tone flat. No adjectives. The power in this letter comes from it being boring and correct.
Rung Three: Seven Days' Notice, With the Ground Stated
This is the rung nobody writes about properly, and it's the one with actual teeth.
If your appointment is a construction contract under the Housing Grants, Construction and Regeneration Act 1996 — and agreements to do architectural or design work in relation to construction operations are expressly covered — section 112 gives you a statutory right to suspend performance of any or all of your obligations for non-payment of a notified sum. The condition is that you give the paying party not less than seven days' written notice of your intention to suspend, stating the ground. The 2009 amendments also entitle you to a reasonable amount for costs and expenses reasonably incurred as a result of the suspension, and to an extension of time.
The exclusion that catches small practices: section 106 takes contracts with a residential occupier outside the Act. If you're doing a rear extension for the people who live in the house, you have no statutory suspension right and no statutory right to adjudicate. You have whatever your appointment gives you — which is why the suspension clause in the standard RIBA professional services contracts matters so much on domestic work. Open your actual edition and find the clause before you draft anything. Don't rely on a half-memory of a clause number from a different year's form.
The notice itself is short, and it must be unmistakably a notice:
Notice of Intention to Suspend Performance
Under clause [x] of our appointment dated [date] and section 112 of the Housing Grants, Construction and Regeneration Act 1996, we give notice of our intention to suspend performance of all of our obligations under the appointment.
The ground for suspension is non-payment of the sum of £[x], being the notified sum in respect of invoices [numbers], which fell due on [dates] and in respect of which no pay less notice has been served.
Unless payment in full is received, suspension will take effect on [date — at least seven clear days from service, or longer if your appointment says so] and will continue until payment is made.
That's it. One page. No paragraph beginning "As you will appreciate".
What Suspension Actually Means — and What It Never Means
Suspension stops you working. It does not stop you being an architect with duties.
Things that continue regardless of who owes you what: your duty of care in respect of work already done; your obligations under the ARB Architects Code, including Standard 10's expectation that you deal with disputes and complaints appropriately; and any safety-critical information in your possession. If you know something that bears on whether the building is safe, you say it. Withholding a safety-critical instruction as leverage is not a negotiating tactic. It's the end of your career, and the end of your PI cover along with it.
The practical decisions during suspension, in the order they'll hit you:
Deliverables already produced. Handing over the drawings is usually not the question — the licence to use them is. Standard appointments generally make the copyright licence conditional on payment of fees. Check yours, quote it in the notice if it's there, and don't assert a right you haven't actually got.
Live planning and building control submissions. You are the agent on record. Suspension doesn't change that, and a consultation response deadline doesn't pause because you're unpaid. What we'd do in practice: tell the client in writing, specifically, which live deadlines exist, that you will not be responding to them during suspension, and what the consequence is — an application refused for want of a response is a real loss that a client may later try to hang on you. Put the risk back where it belongs, in writing, dated.
Site instructions. Stop issuing them. But tell the contractor's point of contact and the client that you've stopped, so nobody builds something on the assumption that you're still watching.
When They Say the Invoice Is Wrong
Different ladder entirely. Three moves.
First, get the dispute in writing and itemised — which line, which amount, on what basis. "It feels like a lot" is not a dispute, it's a mood, and asking for specifics politely is often enough to end it.
Second, ask them to pay the undisputed portion immediately. A client disputing £2,000 of a £9,000 invoice has no basis for sitting on the other £7,000, and asking for it separates the genuine argument from the convenient one.
Third, answer the disputed part with the record, not with your feelings about it. This is where the invoice narrative you wrote months ago either saves you or sinks you. "Stage 3 fee — 40%" is an invitation to argue. "Stage 3 developed design, per clause 4 and the schedule of services: GA plans 2100–2106 issued 12.03, sections 2200–2203 issued 19.03, structural coordination meeting 26.03, revised layouts following your instruction of 02.04" is not arguable, because it's a list of things that either happened or didn't.
If your invoices don't read like that, fix that before you fix anything else. The record you can produce on demand — stage, deliverable, date, instruction, payment received — is the whole ballgame, and the reason we built invoicing into the Cashflow tool off the fee stages themselves rather than as free text you retype each month.
The Counterclaim You Are Inviting
Before you issue any claim, read your PI policy. Most policies require you to notify circumstances that might give rise to a claim, and a fee dispute is very often exactly that — because the standard response to being sued for fees is to allege negligence, which converts your £8,000 debt claim into a defence your insurer is running. Notifying early is not an admission of anything. Notifying late can prejudice cover. Call your broker before the solicitor.
Adjudication, Mediation, or Court
Three routes, and they are not interchangeable.
Adjudication — available as of right under section 108 of the Construction Act where the Act applies, at any time, with the adjudicator's decision binding until finally determined. It's fast and the decision is enforceable. It's also not free, and on a four-figure fee debt the adjudicator's costs can swallow the point. Best suited to commercial clients and substantial sums.
Mediation or RIBA conciliation — slower, cheaper, non-binding, and the only route that has any chance of leaving a working relationship intact. Worth proposing if the client is disputing rather than ghosting, and if you'd genuinely still like to finish the job.
County court — for straightforward debt where the client has simply not paid. In England and Wales the small claims track handles claims up to £10,000, which covers a lot of domestic fee disputes. Before you issue against an individual or a sole trader, the Pre-Action Protocol for Debt Claims applies: you must send a letter of claim with the prescribed information sheet and reply form, and allow 30 days for a response. Skip that step and the court can penalise you on costs for it.
One thing to weigh honestly: once you issue, the relationship is over. Not strained. Over. Decide you're content with that before you press the button, not afterwards.
All of This Was Decided Before You Started
Work the ladder backwards and every rung depends on something you did at appointment stage.
The suspension notice only works if there's a suspension clause and a payment term with a stated due date. The interest only works if the clause says so or the client is a business. The disputed invoice only survives if the narrative ties to a schedule of services. The debt only stays small if you invoiced monthly inside long stages instead of waiting to the end of Stage 4 and discovering, at £24,000 of exposure, that the client's funding never existed. That last one is really a cash flow design problem, and we've written about how to shape the money in and out of a practice separately.
Four things to put in the next appointment, in order of how much grief they save:
A deposit before you draw a line. The single most reliable filter for clients who can't or won't pay.
Monthly invoicing within stages, not on stage completion. Your maximum exposure becomes one month's fee, not one stage's.
A payment term with a named consequence on the day after. Fourteen or thirty days, your choice — but the clause must say what happens on day fifteen or thirty-one, including interest and the right to suspend on seven days' notice.
A copyright licence expressly conditional on payment of fees due.
None of that is aggressive. It's the same information a contractor would put in a tender and nobody blinks.
When to Walk
There's a point where the debt is worth less than the time and the risk of chasing it, and the honest answer is to write it off, terminate properly under the appointment, hand over what you're obliged to hand over, and get your attention back onto work that pays. A six-year limitation period for a simple contract debt under the Limitation Act 1980 means you can always change your mind later; you cannot get the six months back that you spent furious about it.
The practices that get paid aren't the ones with the sternest emails. They're the ones whose appointment said exactly what would happen, whose invoices read like a record of work rather than a demand, and who did the thing the appointment said on the day it said to do it — calmly, in writing, without malice, and without a single exclamation mark.
