Hire the strongest technology leader you can reach, place that person in front of the engineering team on the first morning, and let the decisions settle over the opening month. Boards take that route because it moves quickly and reads as decisive, and the assumption beneath it is fair: anyone who has run a technology function before will find the calls that need making inside a fortnight.
The assumption is sound. The fortnight is where the money goes, because an interim chief technology officer who arrives without an agreed boundary takes the calls that look available and leaves the awkward ones alone. Cloud spend keeps accruing. A hiring round stalls. A vendor contract with months left to run gets signed again, since nobody in the room had the authority to stop it. Each of those events looks minor on the day; the cost of each appears at month nine, in a handover that sets out what the interim chose and says nothing about who owns it now.
What good looks like is one short page, agreed before anyone is approached. It covers the decisions, the money and the exit. It takes a day to produce, and it changes the price, the shortlist and the final month of the engagement.
What the mandate page has to set out
The mandate is a table of decisions, one row per call, built with the chief executive and the board. Whoever drafts it should have no stake in its size.
Each row gives the decision, in a line a non-technical director could read aloud; the person who owns that decision today; whether it transfers to the interim, stays with the board, or is shared; and the evidence that would show the call was made well. Architecture, vendor selection, hiring above lead level, cloud spend past an agreed threshold, security exceptions and the technical account given to investors all belong on it.
The interim CTO briefing from fractional.quest sets out the Institute of Interim Management's definition of interim management: leadership at board or near-board level over a finite time span, kept apart from a contractor's contract or an agency worker's temporary assignment. That definition earns its place here. A table that moves authority over architecture, spend and the engineering team calls for an interim executive. A table that moves a bundle of deliverables calls for a contractor, whatever the advert says at the top, and the gap in cost across a year runs into six figures.
The scope the table has to cover
Moving decisions without moving the ability to act on them leaves the board with a senior opinion. Exec Capital, which places interim CTOs in the UK, sets out what the post owns: technology strategy and board reporting, the engineering function, architecture and build-versus-buy calls, the vendor and partner portfolio, and senior engineering hiring, including the search for the permanent successor.
CodeStringers, an engineering firm that works on both sides of this question, reports that most assignments run between three and nine months and end when the permanent hire starts (its engagement page). The term and the successor search should be planned in the same conversation, because they finish together.
Four steps, run in sequence
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Draft the table and stay with it until every row is complete. Sit with each person who owns a decision today and fill those fields for it. Check: every row identifies one person, and every row is marked transfer, keep or share. A row that needs a committee to settle is not yet a row.
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Size the engagement by decision load. Count the rows marked transfer, estimate how many days a week each one needs through the opening quarter, and turn that into a term in months. Check: you can give a figure for days a week and a figure for months that a finance director would accept without flinching.
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Place the rate against the published bands. Take the day rate, the term and the days a week, and find the band the brief lands in using the table below. Check: you can say which band the rate falls into and what places it there. A rate above every band tells you something about the brief, and it costs less to learn that before signature.
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Fix the handover before the first fee is paid. Settle the test for the last day, the record the assignment will leave behind, and the internal owner who receives it. Check: the receiving person and a fixed end point are agreed and recorded. Nordic Interim advises that the transition plan be settled early in the assignment, in its guide to interim CTO engagements.
Published day rates by mandate type
| Mandate | Published interim CTO day rate |
|---|---|
| Seed to Series A scale-up | £800 to £1,400 |
| Series B or private-equity backed | £1,200 to £2,000 |
| Enterprise or complex legacy estate | £1,800 to £3,000 and above |
| Transformation or turnaround | £1,400 to £2,500 |
Bands are Exec Capital's published 2026 guidance for interim CTO mandates, given at execcapital.co.uk.
Why two prices for the same brief differ
The band explains the range. The mandate explains the position inside it. An interim who replaces a departed leader on a stable platform is a different engagement from one who takes over a migration that is already late, and the published figures overlap heavily for that reason. Toledo Consulting counts urgency among the factors that move interim pricing, alongside scope, contract length, the experience the brief demands and the flexibility agreed in the terms (its cost breakdown). Two identical briefs, one starting next month and one starting after the summer, will not price the same.
Figures in the table below come from fractional.quest's interim CTO briefing, which draws on Exec Capital's market summary and Robert Half's 2026 salary guide.
| Measure | Interim CTO, six months | Permanent CTO, same period |
|---|---|---|
| Rate basis | £800 to £1,800 a day | £160,500 median annual base |
| Cost of the term | £104,000 to £234,000 | Annual base applied to the term, before on-costs |
| On-costs | Employer National Insurance does not apply where the engagement falls outside IR35 | Employer National Insurance, pension, equity and a retained search fee |
CodeStringers sets monthly retainers for near-full-time interim coverage at $3,000 to $15,000, with the heaviest engagements at the top of that band (its engagement page). The same account draws the line a board should keep in view: a consultant hands over a recommendation, while an interim CTO takes the post and owns the outcome.
Where IR35 lands in the decision
The table settles what the person decides; the contract settles how the person is engaged, and in the UK the second question has a tax consequence the first one cannot remove. Status turns on how the assignment runs in practice, and fractional.quest's briefing sets out the tests as substitution, control, and whether either side has to offer or accept further work. A medium or large client makes that determination itself; a small private-sector client leaves it to the interim's own company.
What the opening month has to leave behind
CodeStringers sets out three phases for an assignment: assess, stabilise and hand over, with the assessment taking the opening week or two and ending in a short view of the estate, the team and the risks. By the close of the opening month a board should be able to point at that assessment, a release cadence the team can keep, and a plan for the rest of the term agreed with the chief executive.
What the last day has to show
An interim assignment is judged by what remains after the interim leaves. CodeStringers reports that the handover phase is the one clients most often underrate, and that a clean transfer to the permanent hire belongs in the engagement terms from the outset, instead of being raised in the closing conversation (its engagement page). By the last day the board should be able to point at a decision table with every row closed or transferred, an assessment of the estate that a new leader can read in an afternoon, and a successor either in post or under contract. If any of the three is missing, the engagement was a senior opinion with a day rate attached, and the next nine months will price that.