What is the difference between an MSA and a SOW?

The master services agreement holds the terms that stay the same for every project with a client: payment, IP, confidentiality, liability, termination, law. A statement of work describes one project: scope, deliverables, timetable, price, acceptance. Each SOW is a separate contract on the MSA's terms, so a new project needs only a new SOW.

Who owns the work product?

Whatever the contract says, and if it says nothing, the supplier keeps the copyright. The usual position is that the client owns bespoke deliverables on payment, the supplier keeps its pre-existing tools and know-how and grants the client a licence to use them within the deliverables.

What is change control?

A written process for changing scope, price or time after a SOW is signed: either side proposes a change, the supplier quotes the effect, nothing changes until both sign. Without it, scope creep is paid for by the supplier and disputed by the client.

What liability cap is normal for services?

A cap at the fees paid under the relevant SOW in the previous twelve months, or a fixed figure if that is low, with indirect loss excluded, is a common starting point. Death, personal injury caused by negligence and fraud cannot be excluded under the Unfair Contract Terms Act, and a cap must be reasonable to be enforced.

News & Insights/Customers · 3 October 2026 · 7 min read

Master services agreement and statement of work: how to contract for services without starting again every time

An agency with twenty clients should not have twenty different contracts. One set of master terms, signed once, and a one-page statement of work for each project, is how services businesses stop renegotiating liability every time they quote. Here is how the two documents divide the work.

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01The structure

The master services agreement is signed once with each client and contains everything that does not change from project to project. The statement of work is signed for each project and contains only what is specific to it. When the two conflict, the MSA usually wins, unless the SOW says expressly that it overrides a named clause. The result: a new project is a short document that both sides can read in ten minutes, because the hard terms were agreed at the start of the relationship.

02What goes in the MSA

Engagement and SOWs. How a SOW is formed (signed by both, or an email confirmation), that each SOW is a separate contract, and what happens to SOWs if the MSA ends.

Payment. Invoicing cadence, payment days, interest on late payment (a business can claim statutory interest under the Late Payment of Commercial Debts (Interest) Act 1998, currently 8 per cent over base, plus fixed compensation), expenses, and the right to suspend work when invoices are overdue.

Intellectual property. Bespoke deliverables transfer to the client on full payment; the supplier's pre-existing materials, tools, templates and know-how stay with the supplier and are licensed to the client for use within the deliverables; third-party components (open source, stock, fonts) are identified and licensed on their own terms. Say who owns improvements to the supplier's tools made during the work.

Confidentiality and data. Mutual confidentiality, and a data processing agreement attached if the supplier handles personal data for the client.

Warranties and liability. Reasonable skill and care; deliverables will materially conform to the SOW for a warranty period, with re-performance as the remedy; a cap on liability tied to the fees under the SOW concerned, indirect loss excluded, and the exclusions the law does not allow carved out.

Term and termination. The MSA runs until terminated on notice; SOWs run to completion; either side may terminate for material breach unremedied within a period, or insolvency; on termination the client pays for work done and the supplier hands over work in progress.

Non-solicitation of each other's staff for a period, which matters when the supplier's people sit in the client's office for months.

03What goes in the SOW

Scope and deliverables, described so that a stranger could say whether each was delivered.
Out of scope, which is as useful as in scope.
Timetable and milestones, and what each side must provide (content, access, decisions) for the timetable to hold.
Price: fixed, time and materials with a cap, or a retainer; and what triggers each invoice.
Acceptance: how deliverables are tested, how long the client has to accept or reject, and that silence after that period is acceptance.
Named people on each side, and any special terms for this project.

04Change control

Scope changes are where services contracts go wrong. The MSA should contain a change procedure: either party may request a change in writing, the supplier responds with the effect on price and time, and nothing changes until both sign a change note. Clients accept this readily when it is in the document from the start; they resist it when it appears as an argument after the fact.

05The short version

Sign the master services agreement once per client, then a statement of work per project; keep IP, liability and payment in the MSA and scope, price and dates in the SOW; run every scope change through change control. The template (£39) contains both documents with the notes. Freelancers and single engagements can use the shorter contractor agreement instead; software projects the freelance developer agreement.

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