The short version
- Match the document to the deal: a service agreement for one defined engagement, a consulting agreement where you are paid for judgement rather than a deliverable, a master agreement with statements of work once projects repeat.
- The payment clause does not control payment. Acceptance does. "Net 30 following acceptance" with no defined acceptance process has no due date at all.
- Add deemed acceptance: deliverables are accepted unless rejected in writing, with specific reasons, within a stated number of days.
- A right to suspend work for non-payment is worth more than a right to terminate. Termination ends your leverage; suspension is the leverage.
A services contract has to answer three questions that pull in different directions: what exactly is being delivered, what happens when it is not, and when does money move. Most agreements answer the first at length, the second not at all, and the third in a sentence that quietly depends on the second.
Which of the three documents you actually need
Three shapes cover almost every services deal. Choosing the wrong one shows up later as either a negotiation you did not need or a clause you do not have.
| When it fits | What it has to carry | Where it fails | |
|---|---|---|---|
| Service agreement | One engagement, one supplier, a defined output | Legal terms and scope in a single document | The second project restarts the whole negotiation |
| Consulting agreement | Advice, expertise and time rather than a deliverable | Rates, availability, conflicts of interest, ownership of recommendations | Nothing defines "done", so payment needs a different trigger |
| Master agreement plus statements of work | A continuing relationship with repeat projects | Legal terms once, scope per project, and a rule for which wins | A project manager signs a scope document with contract terms inside it |
The one people get wrong is the middle row. A consulting agreement sells judgement rather than output, so it cannot borrow the acceptance mechanism a deliverables contract relies on. Where you are paid for advice, the payment trigger has to be time elapsed or a milestone reached — never acceptance of a thing, or the client can withhold payment simply by disagreeing with you.
Services are not goods, and that changes what you can rely on
In the United States, Article 2 of the Uniform Commercial Code applies to transactions in goods. It does not govern a contract for services. That is worth knowing because the protections people assume they have are Article 2 protections. There is no implied warranty of merchantability for consulting work, and no right to reject a deliverable because it fails to conform in any respect — that rule belongs to the sale of goods.
What applies instead is ordinary contract law, where a party who has substantially performed is generally entitled to be paid, with a deduction for what is missing. So the standard against which your deliverable is judged is whatever the contract says it is, and nothing else. If the agreement describes the work as "a website" and says nothing about browsers, load times or content, then a slow website that works in one browser is arguably the thing you bought.
The payment clause does not control payment
Read the fee clause and the acceptance clause together, in that order, and the real due date usually turns out to be later than the one on the invoice. Three triggers, in descending order of how well they work:
- On a date, or on a milestone with a fixed date. "50% on signature, 50% on 30 June." Nothing to argue about. Best for fixed-scope work.
- On invoice, with invoicing tied to a defined event. "Invoiced monthly in arrears, payable 30 days from invoice date." Good, provided nothing in the contract lets them refuse to receive an invoice.
- On acceptance. Fine if acceptance is defined, unbounded if it is not. This is where most services money gets stuck.
Where the money actually is between delivery and payment
Day 0
Deliverable submitted
You are done. No payment obligation exists yet.
Day 0–?
Acceptance window
Undefined here means the clock never starts. This is the gap.
Day 10
Deemed accepted
Only if the contract says silence counts as acceptance.
Day 40
Net 30 falls due
Thirty days from acceptance, not thirty days from delivery.
Deemed acceptance is the clause that gets you paid
The mechanism is simple and almost never resisted, because it is fair to both sides. Deliverables are deemed accepted unless the client gives written notice of rejection within a stated period, and that notice has to identify the specific respects in which the deliverable fails to meet the criteria in the statement of work.
Three details make the difference. Set the window in business days and keep it short — five to ten is normal. Require reasons, so "we are not happy with it" is not a valid rejection. And cap the loop: after two rounds of rejection and correction on the same deliverable, either the parties escalate or the client pays for what has been done and takes the work as it stands. Without a cap, an unlimited right to reject is an unlimited right to unpaid revisions.
Change control, or the scope you agreed is not the scope you deliver
Scope creep is not a personality problem, it is a missing clause. Requirements genuinely change during a project; the clause exists to make the change visible and priced rather than absorbed. Any variation to scope, timeline or fee takes effect only when recorded in writing and agreed by both sides — and until it is, the original scope stands.
Add a dependency clause alongside it. Most delay in professional services is caused by the client — content not supplied, access not granted, an approver on holiday. Write down what the client has to give you and by when, and state that the timeline extends day for day where they do not. That single paragraph turns "you are late" into a shared problem with a written record.
Read the full service agreement template
The complete text, free — services and deliverables, compensation, IP, termination and general provisions, published on the page. Copy it or download PDF or Word.
A right to suspend beats a right to terminate
Almost every services agreement lets you terminate for material breach after a cure period. Almost none lets you stop work if an invoice goes unpaid. That is the wrong way round. Termination is a nuclear option that ends the relationship and your leverage in the same moment, and if you are owed money for work already done, you have just made collection harder.
Ask for the smaller right: where an undisputed invoice is more than a stated number of days overdue, you may suspend performance on written notice until it is paid, the timeline extends by the period of suspension, and suspension is not a breach. "Undisputed" is the word that makes it acceptable to the other side — a client disputing an invoice in good faith is not exposed to having the project stopped.
Pair it with a rule that intellectual property in the deliverables transfers on payment rather than on creation. Handing over the work and then chasing the invoice is the weakest position in the contract; see who owns the work for how that clause is usually drafted, and the red flags list for the version to push back on.
What the law gives you on late payment, and what it does not
This is jurisdictional, and the gap between jurisdictions is wide.
What you get without a clause, in three places
UK commercial debts
- Late 30 days after invoice or supply, absent an agreed date
- Statutory interest at 8% over base rate
- Fixed debt recovery costs on top
Only what you wrote down
- US business to business
- Interest is whatever the contract says
- No statutory floor to fall back on
US federal contracts
- A proper invoice paid within 30 days of receipt or acceptance
- Interest runs automatically when it is not
- The contractor does not have to ask for it
When an invoice has gone past the point of polite reminders, the next step is a written demand setting out the debt, the contractual basis and a deadline. The mechanics are in how to write a demand letter, and there is a demand letter template to start from.
The rest of the agreement, in order of what it costs you
Before you sign a services contract
- Liability capped, and capped for both parties — not just for theirs.
- Acceptance defined, with a deemed-acceptance backstop and a limit on rejection rounds.
- A change control clause, and a written list of client dependencies with dates.
- Suspension for non-payment of undisputed invoices, plus interest on late payment.
- IP transferring on payment, with your pre-existing tools and know-how carved out.
- Your subcontractors permitted, or at least permitted with consent not unreasonably withheld.
- Non-solicitation of your staff, running for a defined period after the engagement ends.
- Insurance levels you actually hold, not levels the template suggested.
- A named process for disputes before litigation — escalation to principals, then mediation.
The last one is worth more than it looks. Most services disputes are about expectations rather than law, and a clause that puts two senior people on a call before anyone instructs a solicitor resolves a large share of them at a cost of one hour.
If you take one thing from this: write down what "done" means before you start, and write down what happens if the client says nothing. Those two sentences prevent more unpaid invoices than any payment term you could negotiate.
Sources
General information, not legal advice. This guide explains how these documents and rules generally work. Law varies by jurisdiction and changes, and none of it is applied to your circumstances here. For anything consequential, consult a licensed attorney where you are.
Frequently asked
Do I need a master services agreement or just a service agreement?
One project, one contract — a standalone service agreement is simpler and perfectly adequate. Move to an MSA with statements of work once you expect a second project with the same counterparty. The saving is not in paperwork but in negotiation: the legal terms are argued once, and every later project starts from an agreed baseline with only scope, price and dates to settle.
What is a deemed acceptance clause?
A clause treating a deliverable as accepted if the client does not reject it in writing within a set period, usually five to ten business days, giving specific reasons tied to the agreed acceptance criteria. It exists to stop the payment clock being held open indefinitely by silence, and it is standard enough that asking for it rarely causes an argument.
Can I charge interest on a late invoice?
It depends where you are. In the UK, statutory interest on late commercial debts applies between businesses whether or not the contract mentions it. In the US there is no general federal right between private businesses, so interest is only available if your contract provides for it. Federal agencies are a separate case and owe interest automatically on late payment of a proper invoice.
Should the service agreement or the statement of work take precedence?
Usually the master agreement on legal terms and the statement of work on commercial ones, stated explicitly in a precedence clause. Without it, a later-signed SOW can be argued to override the liability cap or the IP terms you negotiated, simply because it came second — which is not a decision anyone intended to make.
What happens if the client keeps rejecting deliverables?
That is a drafting failure rather than a client problem. A rejection right with no limit is an unlimited right to free revisions. Cap it: after two rejection-and-correction cycles on the same deliverable, either the matter escalates to named senior people or the client pays for work performed and takes the deliverable as it stands. Agree the cap before the first submission, not during the third.