คู่มือนี้ยังไม่ได้แปลเป็นภาษาของคุณ — กำลังแสดงฉบับภาษาอังกฤษ
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's 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're reachable and responsive within an agreed window, distinct from paying for any specific number of hours.
Be explicit about which one you're offering — "10 hours per month" and "guaranteed availability" are different promises, and conflating them is where retainer disputes usually start.
What belongs in the agreement
Before the first retainer payment, put in writing:
- What's 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's 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.
Invoicing a retainer
A retainer invoice is usually simpler than a project invoice: one line for the retainer fee for the period, issued at the start of that period (since you're being paid for the period ahead, not work already done). If the client used hours beyond what the retainer covers, itemize the overage as a separate line so it's clear what's included and what's extra.
Track usage even when the client doesn't ask
Keeping your own record of hours used against the retainer — even informally — means you're never caught off guard by an overage conversation, and 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's actually covering.