Most solo businesses drift into their pricing model rather than choosing it. You take on a project because someone asked, then another, and a year later your income is a series of unrelated spikes. Or you agree to “a few hours a month” for a client you like, and eighteen months on you’re doing three times the work for the same fee.
Project fees and retainers are both good models. They just fail in different ways, and the failure modes are predictable enough that you can design around them.
What each model is actually selling
A project fee sells a defined outcome: a website, a brand identity, a migration, a report. The client is buying a finished thing, and the scope is what makes the price defensible. When the outcome is delivered, the engagement ends.
A retainer sells reserved access: a set amount of your capacity each month, or an agreed set of ongoing responsibilities. The client isn’t buying a deliverable, they’re buying the certainty that you’ll be there. That difference matters, because it changes what the client thinks they’re owed when a month is quiet.
Confusing the two is where most retainer resentment comes from. If you sell access but your client believes they bought a fixed list of deliverables, every slow month feels like they’re being overcharged — and every busy month feels to you like you’re being underpaid.
When project fees are the right call
Project work suits you when the job has a natural end, the scope can be written down, and the value is concentrated in the delivery. It also pays better per hour when you’re good at it: as you get faster, your effective rate goes up, because you’re charging for the result rather than the time.
The cost is volatility. Project income arrives in lumps, with gaps between engagements that you have to fund yourself, and every completed project puts you back into selling mode. If most of your revenue is project-based, you’re running a business with a permanent sales cycle attached.
Two things make project pricing hold up:
- A written scope with an explicit boundary. Not just what’s included, but what isn’t, and what happens when the client wants something outside it. “Additional rounds billed at $X” is a sentence that saves entire relationships.
- Staged payments. A deposit before starting, one or more payments at milestones, and the balance on delivery. Never let the amount you’re owed grow larger than you’re comfortable losing.
When a retainer is the right call
Retainers suit ongoing responsibilities — maintenance, advisory work, content, bookkeeping, anything where the client’s need doesn’t stop. They give you a revenue floor you can plan around, and they cut your selling time dramatically, because a renewed month costs you nothing to win.
The trade is a ceiling. Retainers cap what you can earn from that client, and they quietly expand: scope creep in a retainer doesn’t show up as a change request, it shows up as a slowly heavier month that nobody ever renegotiated.
Structure the retainer so the boundary is visible:
- Cap the capacity, not just the deliverables. “Up to 20 hours a month” or “up to four articles a month” gives you a line to point at.
- Decide the rollover rule up front. Unused hours either expire at month end or roll over for one month — pick one and write it down. Unlimited rollover turns into a liability you’ll be working off for a year.
- Set a review date. Every six months, look at what the retainer has actually become and reprice it. Retainers that are never reviewed only ever move in the client’s favour.
Pricing each one honestly
For a project, price from the outcome, then sanity-check against effort: estimate the hours you genuinely expect, add a buffer for the revisions you know are coming, and multiply by your target rate. If the outcome-based number is well above that floor, charge the outcome-based number. If it’s below, either the scope is bigger than the client thinks or the project isn’t worth taking.
For a retainer, price from reserved capacity, not from an optimistic average. You’re holding space in your schedule whether or not the client uses it, so the fee has to be worth the space. A common mistake is discounting a retainer heavily “because it’s guaranteed” — a modest discount for predictability is fair, but a deep one just means your best clients pay your worst rate.
Most solo businesses want both
The healthiest mix for a business of one is usually a base of retainers covering your fixed costs, with project work layered on top for the upside. The retainers mean a quiet quarter isn’t an emergency. The projects mean a good quarter can be genuinely good.
A practical target: retainers that cover your baseline personal and business costs, and project work as the surplus that funds your buffer, your taxes and your growth. Once you know which revenue is your floor and which is your upside, the whole business feels less precarious, even if the annual total hasn’t changed.
Where Billable comes in
Choosing between models is easier when you can see what each one is actually earning you. Billable tracks every invoice you send — recurring retainer bills and one-off project milestones alike — so you can tell at a glance how much of your income is the reliable floor and how much is the variable upside.
It handles the recurring invoicing that retainers depend on, keeps milestone payments from slipping through the cracks, and chases overdue invoices automatically so you’re not the one sending the awkward reminder. It’s built for a business of one, at a flat $19 a month. See what your revenue mix really looks like.