Hourly vs project vs retainer

The three models differ in who carries the risk of the work taking longer than expected. Everything else follows from that.

Most comparisons frame this as a pricing question. It is closer to an insurance question, and the premium is paid in utilisation.

Who carries the overrun

Hourly. The client does. Work takes longer, they pay more. You are protected from scope creep and exposed to nothing except the client noticing the total.

Fixed project. You do. Every hour past the estimate comes out of your margin. In exchange, efficiency is yours to keep: finish in half the time and the fee does not change.

Retainer. Shared, and blurred. A monthly amount buys access or a capped volume, and both sides trade certainty for flexibility.

That is the whole structural difference. The pricing follows.

What each does to your utilisation

This is the part that changes the number, and it is measurable rather than theoretical.

The utilisation column is an estimatenot measured, and it is where the whole comparison lives.

Retainers raise it because the sales cycle is paid once and then amortised over months. Fixed projects lower it because every engagement needs an estimate, and estimates that do not convert are unpaid hours.

A retainer at $98/hr and a project at $129/hr can be the same business outcome. Comparing headline rates across models is comparing different things.

When each one is the right answer

Hourly fits work with genuinely unknown scope — discovery, debugging, anything where the answer determines the effort. It is also the honest model when a client keeps changing their mind, because it prices that behaviour instead of absorbing it.

Its weakness is structural: it caps your income at your hours and it punishes you for getting faster. Every efficiency you develop reduces your own invoice.

Fixed project fits well-specified work you have done before. It rewards expertise directly — the tenth time you build the same thing takes a third as long at the same fee.

Its weakness is that “well-specified” is rarer than it sounds, and the cost of getting it wrong falls entirely on you. A fixed price without a written scope and a change process is a fixed price on undefined work.

Retainer fits ongoing need: maintenance, advisory, a reserved share of your capacity. It is the best of the three for cash flow, which for a one-person business matters more than margin.

Its weakness is drift. Retainers quietly expand until the monthly fee buys twice what it was scoped for, and the correction is a conversation nobody wants to have. A retainer needs a stated boundary — hours, deliverables, response time — or it becomes a salary without the benefits.

The cash-flow argument, which usually wins

For a one-person business, predictability beats margin more often than the arithmetic suggests. A retainer at a lower effective rate means knowing what January looks like, and knowing what January looks like changes what you can commit to in October.

It also does something for tax: steady income across the year makes quarterly estimated payments straightforward, where a lumpy project year pushes you toward the annualized method and its extra paperwork.

What does not change

The tax treatment is identical. Self-employment tax at 15.3% on 92.35% of net profit irs.gov applies the same way whether the money arrived hourly, per project, or monthly. The IRS does not care how you invoiced.

What changes is when it arrives, and that affects quarterly payments rather than the total.

Where this stops applying

The utilisation figures above are estimates and yours will differ. Measure a month before you rely on them — the utilisation guide shows how, and it takes about ten minutes with last month’s invoices.

And none of this decides what the work is worth. All three models can be priced above or below value; they only determine who absorbs the variance.

Related: what to charge · utilisation · contractor vs salary · the rate floor calculator