Retainer vs fixed price: how to price agency work

Use fixed price when the work has a clear start, end and scope, like a website build. Use a retainer when the work is ongoing and the client needs reliable access to your team, like maintenance, content or support. Hourly billing suits unpredictable work, and value pricing works when you can tie the fee to a measurable business outcome. Most healthy agencies use two or three of these at once.

Below is how each model works, when it fits, where it goes wrong, and how to build a retainer that protects your margin.

#The four pricing models in one table

#Fixed price: clear for the client, risky for you

Fixed price is what most clients want for a project. They know the number up front, it fits a budget line, and comparing proposals is easy.

When it fits:

• The deliverables can be listed precisely (14 page templates, 400 products migrated).
• You've built something similar before and can estimate with confidence.
• The client has a fixed budget and a launch date.

The risks:

• Every hour you underestimate comes out of your margin.
• Vague scope invites "while you're at it" requests. Our guide to scope creep covers how to handle them.
• Slow client feedback stretches the project without extending the fee.

How to protect yourself: a precise scope and a "not included" list in the proposal (see our web design proposal template), a limited number of revision rounds, a change request process, and milestone payments so cash arrives as work is approved.

Worked example: pricing a fixed fee

Say you estimate a site build at 160 hours and your target effective rate is $150 per hour.

• Base estimate: 160 × $150 = $24,000
• Add a 15% contingency for unknowns: $24,000 × 1.15 = $27,600
• Round to a clean number: $27,500, billed 40% / 30% / 30% at start, design approval and launch.

If the project finishes in 150 hours, your effective rate is about $183. If it runs to 200 hours, it drops to $137.50. Track hours even on fixed fees, or you'll never know which projects actually made money.

#Retainers: predictable revenue, if structured well

A retainer is a recurring fee, usually monthly, for ongoing work. It smooths your cash flow and gives clients reliable access to people who already know their business.

When it fits:

• The work never really ends: site care, content, SEO, paid media, design support.
• The client values responsiveness more than a line-item quote for each task.
• You've already worked together, so both sides know what "a normal month" looks like.

The risks:

• Underuse. The client pays for 20 hours, uses 6, and starts wondering why they're paying.
• Overservicing. The client uses 35 hours on a 20-hour plan, and nobody notices until the margin is gone.
• Drift. Without regular reporting, the retainer feels like a subscription the client forgets the value of.

#How to structure a retainer

Hours bundle vs deliverables

There are two main ways to define what a retainer buys.

Hours bundle: the client buys a block of hours each month, for example 20 hours for $3,000. Simple to explain, flexible for mixed requests, and easy to track. The downside is that it keeps the conversation about hours rather than results.

Deliverables retainer: the client buys a set output each month, for example four blog posts, one landing page and monthly site updates for $4,500. Easier for the client to value, but you need a clear definition of each deliverable and a rule for what happens when they want something different.

Many agencies combine them: a defined deliverable set plus a small hours bundle for ad hoc requests.

Rollover rules

Decide in advance what happens to unused hours. Common options:

• No rollover. Unused hours expire at month end. Cleanest for you, can feel harsh to clients.
• Limited rollover. Up to a cap (say 25% of monthly hours) carries into the next month only, then expires.
• Quarterly pooling. Hours are tracked across three months, so a quiet month balances a busy one.

Overage rate

When a client goes over their bundle, bill the extra at an agreed overage rate. Set it at or slightly above your standard rate so the retainer stays the better deal. Tell the client before they cross the line, not on the invoice.

Minimum term

Retainers need time to show value. A 3 to 6 month minimum term, then month to month with 30 days' notice, is common. It gives you enough runway to plan staffing and gives the client a clear exit. Write rollover, overage and minimum term into the agreement; our list of 12 clauses every agency agreement needs covers the rest.

Worked example: a 20-hour retainer

In a month where the client uses 24 hours, the invoice is $3,000 + (4 × $165) = $3,660. In a month where they use 16, the 4 unused hours roll over and next month's bundle is 24 hours. The month after that, any unused rollover expires.

#Hourly and time and materials

Hourly billing is honest and low-risk for the agency: you get paid for every hour worked. It works well for discovery phases, technical audits, unclear requirements and small one-off requests.

The downsides are real, though. Clients can't budget easily, they scrutinize every timesheet, and you're penalized for getting faster. If you bill hourly, send estimates as ranges, share a running total, and agree a not-to-exceed amount for anything larger than a few days.

#Value pricing, briefly

Value pricing sets the fee by what the outcome is worth to the client, not by your hours. If a new checkout flow is expected to add $400,000 a year in online sales for a client, a $40,000 fee may be easy to justify, even if it takes you 120 hours.

It works best when the client shares real numbers, the outcome is measurable, and you have a track record in that kind of work. It's hard to use with new clients or for work like brand design where results are diffuse. Most agencies use value thinking to set the top package in a proposal rather than pricing everything this way.

#Moving a fixed-price client onto a retainer

The best time to propose a retainer is before the project ends, while the client is happy and the team knows the site.

1. Plant it in the proposal. Include a monthly care plan as an optional add-on. Even if they decline, the idea is there.
2. List what happens after launch. Two weeks before launch, send a short note: updates, fixes, new pages and campaigns they'll need in the next six months.
3. Use the real data. Look at how many hours of small requests came in during the project. If it was 12 hours a month, propose a 15-hour bundle.
4. Start with a short minimum. A 3-month term lowers the commitment and lets you prove the value.
5. Report monthly. Send a one-page summary of hours used, work delivered and what's next. This is what keeps retainers renewed.

#Which model should you choose?

• Clear deliverables and a deadline: fixed price, with milestone payments.
• Ongoing work and an established relationship: retainer, with rollover rules and a minimum term.
• Unclear scope or small requests: hourly, with estimates and a cap.
• Measurable outcomes and a trusting client: value pricing, at least for your top package.

Whatever you pick, invoice on schedule and follow up when payments slip. Our guide to late invoices has templates for that.

#How Bitrack helps

Bitrack lets you sell fixed-price work with proposals that include packages and optional add-ons, then track time against the project so you can see your real effective rate. For retainers, support hours handle monthly hour bundles, rollover and usage, and clients can raise tickets in the client portal. Invoices support schedules, reminders and partial payments. See invoicing for details.

Pick the model that fits the work, write the rules down, and price with confidence.