Temporary workforce engagement is not one-size-fits-all. Different workers, assignments and sectors may require different engagement routes. The important point is not only choosing a route, it is being able to evidence why that route was appropriate. Payroll, tax, worker communication and compliance evidence all flow from the engagement route.
What is an engagement route?
An engagement route is the basis on which a worker is engaged and paid. It may involve PAYE employment, CIS subcontractor arrangements, off-payroll working / IR35 considerations, or other specific sector or assignment structures.
The correct route depends on the facts: the nature of the work, who controls it, whether substitution is realistic, whether the worker is genuinely in business on their own account, contract terms, working practices, client requirements, tax legislation, sector norms and risk appetite.
Why PAYE matters
PAYE is the most straightforward route in many cases because tax and National Insurance are deducted through payroll. But PAYE still needs proper controls over worker records, tax codes, payroll dates, gross pay, deductions, pension position, payslip clarity, HMRC reporting and corrections.
Why CIS matters
The Construction Industry Scheme applies to certain construction operations and subcontractor arrangements. Where CIS is used, agencies need to understand whether the work falls within CIS, whether the subcontractor has been verified, what deduction rate applies, how invoices or self-billing are handled, how deductions are reported, what records are held, how any admin fee is explained and whether VAT or domestic reverse charge issues apply.
CIS is not simply "self-employed payroll". It requires its own controls and evidence.
Why IR35 matters
IR35 and off-payroll working rules can be relevant where workers provide services through intermediaries. Agencies and clients may need to consider who is responsible for status determination, whether the rules apply, whether working practices match the contract, how status decisions are communicated, what evidence supports the decision and how disputes are handled.
The danger of route drift
Route drift happens when a worker is placed into one engagement route at the start but the facts change over time:
- a short assignment becomes long-term;
- the worker's duties change;
- the client increases supervision or control;
- a subcontractor starts looking like an employee;
- paperwork is not updated;
- payroll treatment no longer matches reality.
Agencies need review points, not just initial decisions.
What good evidence looks like
- route selected;
- reason for the route;
- source information used;
- person responsible for review;
- contract issued;
- worker communication;
- payroll treatment;
- relevant tax or statutory outputs;
- review dates;
- exceptions or changes.
Final thought
PAYE, CIS and IR35 are not just technical labels. They shape the whole worker experience, payroll process and compliance evidence trail. Agencies that treat engagement route decisions as a controlled process will be better placed to protect margin, reduce risk and build trust.