Evrenus Fırat Polat · ·
Most billing pays for work already done. A retainer flips that: the client pays upfront for a set amount of your time or availability over a period, whether or not they use all of it. It is common for lawyers, consultants, and agencies with ongoing client relationships.
What a retainer actually buys the client
Depending on how you structure it, a retainer typically covers one of two things:
- A block of hours or deliverables per period. For instance, 10 hours of consulting per month, use it or lose it (or, in some agreements, roll it forward).
- Priority availability. The client pays to guarantee you are reachable and responsive within an agreed window, distinct from paying for any specific number of hours.
Be explicit about which one you are offering. "10 hours per month" and "guaranteed availability" are different promises, and conflating them is where retainer disputes usually start.
Why offer one
For you, a retainer brings predictable income, easier planning, and fewer sales conversations. For the client, it brings faster response, a priority place in your schedule, and often a lower hourly rate. It also helps with revenue forecasting, because retainer income is committed ahead of time.
What belongs in the agreement
Before the first retainer payment, put in writing:
- What is included. Hours, deliverables, or availability, defined specifically enough that neither side has to guess.
- What happens to unused time. Does it roll over, expire, or convert to a credit? Silence on this point is the single most common source of retainer disagreements.
- The rate for work beyond the retainer. If the client needs more than what is covered, what do additional hours cost? Our retainer calculator and hourly invoice calculator can help you set consistent rates for both.
- The billing cycle and renewal terms. Monthly, quarterly, and whether the retainer auto-renews or needs to be reconfirmed.
- Response times and communication channels, if availability is part of the deal.
- Notice period for ending it, such as 30 days in writing.
- What is excluded, like travel or third-party costs.
For legal terms, such as how fees held in advance must be treated, rules vary by country and profession. Ask a lawyer or accountant if you are unsure.
Worked example: a monthly consulting retainer
A marketing consultant offers 12 hours a month for $1,800. The normal rate is $175 an hour, so 12 hours would cost $2,100.
- Retainer rate per hour: $1,800 ÷ 12 = $150.
- Discount for the client: $175 − $150 = $25 an hour, or about 14.3% off.
- Overage rate: $175 an hour (the normal rate).
Month 1: client uses 9 hours. Unused: 3 hours. The agreement says unused hours expire. The consultant still earned $1,800, and the effective rate is $1,800 ÷ 9 = $200 an hour.
Month 2: client uses 15 hours. Overage: 15 − 12 = 3 hours × $175 = $525. The month 2 invoice for work done is $1,800 (next month's retainer, billed in advance) plus $525 overage = $2,325. Tax, if it applies, is added per local rules.
Over the two months, the consultant billed $1,800 + $1,800 + $525 = $4,125 for 24 hours of work. That is about $172 an hour on average. A rollover policy would change this: if month 1's 3 unused hours had carried over, month 2 would have 15 included hours and no overage, so total billing would be $3,600.
Run your own numbers before you set the price. Does the retainer rate still cover your costs on a quiet month? See pricing your services.
Invoicing a retainer
A retainer invoice is usually simpler than a project invoice. It has one line for the retainer fee for the period, issued at the start of that period, since you are being paid for the period ahead rather than work already done. If the client used hours beyond what the retainer covers, itemize the overage as a separate line so it is clear what is included and what is extra. Since the same invoice repeats, see recurring invoices for setting up the schedule. Create each one in the invoice generator.
Track usage even when the client doesn't ask
Keeping your own record of hours used against the retainer, even informally, means you are never caught off guard by an overage conversation. You can show the client exactly where their retainer went if they ever ask. It also tells you, well before a renewal, whether the retainer is priced correctly for the work it is actually covering. A monthly summary built from timesheets works well. Send an alert when 80% of the hours are used.
Common mistakes
- No rule for unused hours. Decide and write it down.
- Unlimited requests for a fixed fee. Define scope, or you will work far more than you are paid for.
- Letting overage go unbilled. If you work extra hours without charging, the client learns that the limit is not real.
- Not reviewing the price. Review the retainer every 6 to 12 months against actual hours.
- Treating the retainer as a loan. Funds paid in advance are for future work. Keep a clear record of the balance.
FAQ
Is a retainer the same as a deposit?
Not quite. A deposit is a one-time advance toward a specific project, taken off the final bill. A retainer is a recurring payment for ongoing access. See invoice deposits.
Should unused hours roll over?
It is a business choice. Expiry protects your capacity planning. Limited rollover, for example one month only, keeps clients happy. State the rule clearly.
What if the client wants to cancel?
Follow the notice period in the agreement. Provide a final report of hours used and settle any balance.
Can I raise a retainer price?
Yes, with notice. Give 30 to 60 days in writing and apply it from the next billing cycle.