Fractional COO or a chief of staff?
A fractional COO owns how the company runs and has the authority to change it. A chief of staff carries what the chief executive cannot this quarter, from every room, every day. The COO costs £5,367 to £9,967 a month at two days a week, and a fractional chief of staff prices within the same band. Rebuild the operating model with the first; keep it running with the second.
Below is what each one actually owns, what they cost on the same basis, how each one fails, and when to pick the other one.
| A fractional COO | A chief of staff | |
|---|---|---|
| Who owns the outcome | How the company actually runs: process, planning, accountability | Whatever the chief executive needs carried this week |
| Commitment | One to three days a week, flexing with the work, no end date assumed | Full-time and in the building, attached to the chief executive |
| How it is priced | £700 to £1,300 a day | A full-time salary, usually below an operations seat, plus the employer costs and the recruitment fee. |
| Typical monthly cost | £5,367 to £9,967 a month at two days a week | No like-for-like monthly figure is published here; see how it is priced |
| How it fails | Being hired to fix the chief executive's diary rather than the operating model, which is an expensive way to buy an assistant. | Asking a chief of staff to restructure a function they have no authority over, which usually ends with a good person leaving. |
| Pick it when | A function is breaking and somebody needs the authority to rebuild it | The problem is the chief executive's capacity rather than the company's structure |
What a chief of staff actually is
A full-time hire attached to the chief executive, carrying whatever the chief executive cannot carry this quarter.
What each one owns
| A fractional COO | A chief of staff |
|---|---|
| How the company actually runs: process, planning, accountability | Whatever the chief executive needs carried this week |
| The operating rhythm, and whether anybody keeps to it | Making meetings, decisions and follow-up actually happen |
| Fixing the function that is breaking, with authority to change it | Being the connective tissue between functions |
| Hiring and structuring the operations team properly | Proximity: in every room, every day, hearing everything |
What neither of them does
Neither owns a function's numbers. If sales are not landing or the product is late, that is a sales or a product problem, and putting an operations seat over it hides the issue rather than fixing it.
How each one fails
The fractional COO: Being hired to fix the chief executive's diary rather than the operating model, which is an expensive way to buy an assistant.
A chief of staff: Asking a chief of staff to restructure a function they have no authority over, which usually ends with a good person leaving.
What they cost, on the same basis
A fractional COO charges £700 to £1,300 a day, which is £5,367 to £9,967 a month at two days a week. A full-time salary, usually below an operations seat, plus the employer costs and the recruitment fee. The monthly and annual arithmetic for the fractional side, against a full-time equivalent, is on the cost page for this seat.
Pick a chief of staff when
- The problem is the chief executive's capacity rather than the company's structure
- You need somebody in the building continuously, hearing everything
- The work is coordination across functions rather than rebuilding one
We would rather say that plainly than win an engagement that was the wrong shape. Nobody pays us to list on the bench, so there is nothing in it for us either way.
When you want both
They sit well together. A fractional COO rebuilds how the company runs, and a chief of staff keeps it running between those sessions.
What a fractional chief of staff does
A fractional chief of staff works one to three days a week alongside the chief executive, usually in a company that has grown past about fifteen people and where the founder has become the bottleneck. The job is leverage: making sure the chief executive's time goes on the few things only they can do, and that everything decided in a meeting actually happens afterwards.
In practice that means owning the leadership team's operating rhythm: the weekly meeting, the quarterly plan, the follow-up on actions and the logistics of the board pack. It often means running one or two cross-functional projects nobody else owns, such as an office move, a systems change, a fundraise data room or the first proper planning cycle. And it means being a second pair of eyes on the chief executive's priorities, with enough seniority to say that something is not worth their time.
What it is not is a function owner. A chief of staff does not run sales, finance or operations, and holds authority only on loan from the chief executive. That is the line that separates the seat from a COO, and the line most often blurred when a company hires one hoping to get the other.
What a fractional chief of staff costs in the UK
No separate band is published for a fractional chief of staff. The people who take the seat usually also hold the COO title and price within the fractional COO band, £700 to £1,300 a day in the UK in 2026. At one day a week that is £2,683 to £4,983 a month, and at two days £5,367 to £9,967, on 46 billable weeks a year.
Where a brief is lighter, mostly the meeting rhythm and project follow-through without the structural calls, expect quotes nearer the bottom of that band. Where it includes running the planning cycle, sitting on the leadership team and holding functions to their numbers, it is a COO brief, and it should be priced and titled as one.
Read next: What a fractional COO costs, month by month.
Chief of staff vs executive assistant
An executive assistant manages the chief executive's time: the diary, travel, correspondence and the preparation for meetings. A chief of staff manages the chief executive's priorities: which meetings should exist, what each one should decide, and whether the decision was carried out. The assistant makes the week run; the chief of staff makes sure it was spent on the right things.
The two work well together and are often confused in hiring. A company that advertises a chief of staff role and describes diary management is hiring an assistant with a bigger title, and will lose a strong candidate within months. A company that hires an assistant and expects them to hold leaders to account has given them a job with no authority. Write the brief from the outcomes first, then pick the title that matches.
| Chief of staff | Executive assistant | |
|---|---|---|
| Manages | Priorities and follow-through | Time, diary and logistics |
| Works with | The whole leadership team | The chief executive and their contacts |
| Judged on | Whether decisions get carried out | Whether the week runs smoothly |
| Authority | On loan from the chief executive | Over the diary |
When a chief of staff should become a COO
The seat has a natural end. Once the operating rhythm runs without them and the projects they carried have owners, a chief of staff either moves into a function or the role grows into operations proper. If the company keeps asking its chief of staff to fix functions, restructure teams and own the operating numbers, it already needs a COO, and the fractional version is the cheaper way to find out how many days of one.
Common questions
Should I hire a fractional COO or a chief of staff?
A fractional COO owns how the company runs and has the authority to change it. A chief of staff carries what the chief executive cannot this quarter, from every room, every day. The COO costs £5,367 to £9,967 a month at two days a week, and a fractional chief of staff prices within the same band. Rebuild the operating model with the first; keep it running with the second.
Is a fractional COO cheaper than a chief of staff?
Not necessarily. A full-time chief of staff is a salary usually below an operations seat, plus employer costs, and a fractional COO costs £5,367 to £9,967 a month at two days a week, so the monthly totals can be close. The choice is about authority: the COO can change how the company runs, and a chief of staff carries what the chief executive cannot.
When is a chief of staff the better choice than a fractional COO?
The problem is the chief executive's capacity rather than the company's structure. You need somebody in the building continuously, hearing everything. The work is coordination across functions rather than rebuilding one.
Can I use a fractional COO and a chief of staff at the same time?
They sit well together. A fractional COO rebuilds how the company runs, and a chief of staff keeps it running between those sessions.