Glossary
Retainer
Also called: retainer agreement · monthly retainer
A retainer is a recurring fee a client pays in advance to secure a provider's availability or a set amount of work each period, usually monthly. Retainers are billed on a schedule rather than per project and may or may not include a fixed number of hours.
Last updated October 13, 2026
Three kinds of retainer
An access retainer pays for availability — the client can call, and you prioritize them — with hours billed separately or not at all. A block-of-hours retainer pre-buys a fixed number of hours each month, with rules for unused and extra hours. A deliverables retainer promises a recurring output (four articles, a monthly report) for a flat fee regardless of hours.
Billing a retainer
Retainers are invoiced on a schedule, typically at the start of each period. The invoice is the same every month for access and deliverables retainers; for block-of-hours retainers it may add overage lines for hours above the block. Recurring invoices remove the monthly manual step and make the client's due date predictable.
Decide in writing whether unused hours roll over, expire, or are credited. Rollover rules are the most common source of retainer disputes and are hard to administer by hand.
Tracking hours against a retainer
Even on a flat retainer, track every hour. It shows whether the fee is still fair, flags clients who consistently exceed their block, and gives you evidence when a client asks what they are paying for.
In Hoursmith
Studio and Agency workspaces can schedule recurring invoices for a fixed retainer fee, for eligible unbilled hourly time and expenses, or a hybrid, with each occurrence sent as a reviewable draft or by guarded auto-send. Hoursmith does not keep a prepaid-hours balance or rollover ledger, so block-of-hours accounting is tracked outside the invoice.