How to Hire Contract Engineers in the UK

ARG sells capacity two ways, and the split is not about seniority or budget. It is about what the vacancy is costing and when.

Contract and interim is immediate capacity: the gap is costing output now, and the question is how fast somebody competent can be on site. Permanent is long-term capacity: the gap is costing capability, and the question is who should hold the role for the next several years. Where both are true at once, the two searches run in parallel rather than in sequence — and running them in parallel is what takes the panic out of the permanent decision.

The most common contract budgeting error is to take a salary, divide it by a number of working days, and treat the result as a day rate. That calculation omits everything a day rate exists to cover.

When quoting a rate, state the basis as well as the number: whether it is a day rate or an hourly rate, how long a day is, how overtime and call-out are treated, whether travel and accommodation are covered on a site-based assignment, and whether the figure is what the contractor receives or what you are invoiced. Those five clarifications settle most of the disputes that arise in the first fortnight of an assignment.

ARG does not restate contract rates in this guide. Where a published figure exists it sits in the sector salary table with its own basis and named sources — the renewables table, for instance, publishes a day rate for Package Manager and shows no annual band at all, because the public data for that role covers day rates only and inventing a permanent equivalent would be a fabrication. The tables are the place to look, not a guide.

This is the half of contract hiring that sits on the client’s side of the line, and the half most often left until a candidate has been chosen. Doing it in that order is how a 72-hour shortlist turns into a three-week engagement.

The framework, in outline. For engagements with medium and large private sector clients, the end client determines whether the engagement is inside or outside IR35, and must issue a Status Determination Statement with its reasoning to the worker and to the party it contracts with, together with a process for the worker to disagree. Companies meeting the small-company thresholds are exempt, and for those engagements the determination stays with the worker’s own limited company. Where an engagement is inside IR35, employment taxes are deducted at source — in practice through an umbrella company or a PAYE arrangement.

That is a summary of a framework, not advice on your engagement. Take your own tax advice on anything marginal. What matters operationally is simply that the determination is a decision you make before the shortlist, and that it changes which contractors will take the work: a role determined inside IR35 and one determined outside attract measurably different pools, and a role whose status is "to be confirmed" attracts the smallest pool of the three.

ARG supplies contract cover through compliant umbrella or PAYE routes and assesses each engagement for IR35, which is the part a client reasonably expects an agency to carry. It cannot make the determination for you where the legislation puts that on the end client.

A contractor who has worked well for six months is the best-evidenced permanent candidate you will ever have: months of observed work in your own plant, against two interviews for everybody else. Converting is a legitimate and common outcome and nobody should be coy about it.

It only goes wrong on the commercials, and it goes wrong for a predictable reason — the conversation happens after a hiring manager has decided. Agree at engagement whether a transfer fee applies, how it is calculated, and after what period of continuous engagement it falls away. Done at the start it is a clause; done at the end it is a negotiation with one side already committed.

The one thing worth checking honestly before converting is whether the person wants it. A career contractor is not a permanent candidate who has not been asked, and a good one will say so.