“Statement of Work” became one of the defining phrases of the off-payroll era.
The phrase is regularly used by clients, recruiters and consultancies, usually to describe engagements that resemble outsourced project work rather than the ordinary supply of contractor labour.
Sometimes this is genuinely the case. However, in other cases, very little has really changed apart from the wording in the paperwork.
A properly structured Statement of Work arrangement can support an outside IR35 position by pointing to a genuine business-to-business project relationship rather than ordinary labour supply.
But the existence of an SoW document on its own proves very little.
HMRC may examine the contractual terms and the circumstances of the engagement when deciding whether the arrangement is a genuine outsourced project or a supply of labour.
What is a Statement of Work?
A Statement of Work, usually shortened to “SoW”, is normally a separate project document attached to a wider consultancy or services contract.
It often defines:
- the project scope
- deliverables
- milestones
- pricing structure
- timescales
- acceptance criteria
- responsibility for defects or rework
In a genuine consultancy-style arrangement, the client is buying a defined outcome or project deliverable rather than simply paying for an individual’s time.
That distinction matters because traditional inside IR35 contractor engagements often revolve around supplying labour on an ongoing basis under client supervision.
A genuine SoW arrangement can look very different in practice.
Why SoW arrangements became more common after the off-payroll reforms
Before the off-payroll reforms arrived in the private sector in 2021, many organisations engaged PSC contractors directly on relatively standard contractor terms.
After the reforms, many clients became uncomfortable with the tax risk associated with direct PSC engagements.
Some organisations moved heavily towards umbrella models.
Others started pushing more work through consultancy structures and SoW frameworks.
The thinking behind it was fairly obvious. A genuine outsourced project can look very different from a contractor simply sitting inside an internal delivery team doing ongoing work under client control.
That does not automatically make every SoW-defined engagement outside IR35.
But a properly implemented project-based structure may help support:
- reduced client control
- clearer project ownership
- commercial separation
- defined deliverables
- supplier-level financial risk
- reduced integration into the client organisation
Some large organisations rebuilt entire contractor engagement models around this approach.
The problem with “fake” Statements of Work
This is where things often become more complicated.
A lot of so-called SoW arrangements are still just labour supply dressed up as consultancy work.
The contractor may still work:
- inside the client team
- under client management supervision
- to client-controlled schedules
- on rolling extensions
- using the same reporting structure as employees
- on ordinary BAU operational work
The contract may describe a consultancy engagement with defined deliverables, but the label placed on the arrangement is not decisive.
The contractual terms must still be identified and the hypothetical direct contract assessed using the normal employment status tests. Other evidence may be relevant when establishing those terms or considering the circumstances in which the services were provided.
See also:
A polished SoW document does little to help if the contractual rights and obligations still amount to employment.
What genuine SoW arrangements often look like
There is no perfect template and no guaranteed contract terms that create an outside IR35 engagement.
But genuine project-based consultancy arrangements often share several common characteristics.
Defined project deliverables
The engagement is usually tied to a specific project outcome rather than indefinite attendance.
Examples might include:
- a cloud migration project
- delivery of a software module
- deployment of new infrastructure
- security remediation work
- production of technical architecture documentation
The client is paying for the delivery of a project or outcome.
That is materially different from simply paying a contractor to work under supervision inside an operational team for an indefinite period.
Milestones and acceptance criteria
Real SoW engagements often contain milestone structures and formal acceptance processes.
The work may be broken into phases with separate deliverables, sign-off stages or payment triggers.
This creates greater commercial separation between supplier and client.
Inside IR35 labour supply arrangements are often much simpler. The contractor submits timesheets and receives payment for attendance regardless of the wider project’s success or failure.
Greater supplier autonomy
The supplier normally retains meaningful control over how the work is carried out.
That may include:
- technical implementation
- scheduling
- resource allocation
- delivery methods
- project planning
Control remains one of the core employment status tests in IR35 disputes.
See also:
Where the client exercises extensive day-to-day supervision of how the contractor performs the work, the wording of the SoW may carry less weight.
Financial risk
Real consultancy projects sometimes involve genuine financial exposure.
Examples include:
- fixed-price work
- delivery penalties
- cost overruns
- milestone obligations
- rework at the supplier’s expense
That looks very different from a contractor simply submitting weekly or monthly timesheets for payment.
See also:
Reduced integration
Outside IR35 consultancy arrangements are often operationally separate from the client’s ordinary internal management structure.
The contractor may have less involvement in:
- internal HR processes
- employee management structures
- staff appraisals
- BAU operational activities
- internal line management reporting
That links closely to wider “part and parcel” principles.
See also:
A Statement of Work alone will not decide IR35 status
This is the point many contractors miss.
A professionally drafted SoW does not automatically determine that a particular role is outside IR35.
A worker’s employment status is still defined using a number of factors, including:
- control
- mutuality of obligation
- substitution
- financial risk
- integration
- overall business reality
See also:
The contract and Statement of Work must set out a genuine project-based arrangement rather than disguising an internal role as an outsourced service.
You can use our IR35 Clause and Reality Checker to compare specific SoW wording with what happens in practice, including scope, control, rectification and financial risk.
The Court of Appeal confirmed in Atholl House that contractual terms cannot simply be disregarded in an IR35 case. However, calling an arrangement a Statement of Work does not determine the contractor’s employment status.
Why some clients still avoid PSC contractors entirely
It is also important to understand the wider commercial reality.
Some organisations moved towards SoW models following the off-payroll reforms.
Others simply stopped engaging PSC contractors altogether.
Many clients concluded that the compliance risk, administrative burden, and potential tax exposure associated with IR35 determinations outweighed the benefits of direct PSC engagements.
That is one reason umbrella company arrangements became far more common after 2021.
A genuine outsourced consultancy project may still fall outside IR35.
But many organisations remain cautious about any structure that could later be challenged by HMRC as disguised labour supply.
The practical reality
The strongest outside IR35 SoW arrangements usually involve genuine project ownership combined with working practices that support the contractual position.
That normally means the contractor or consultancy operates with meaningful autonomy, carries some level of commercial responsibility and delivers defined project outcomes rather than simply filling an internal role.
Once the engagement starts to resemble ordinary supervised labour supply, the existence of a Statement of Work may not provide much protection on its own.