Retainer Invoice Template
Create professional retainer invoices for ongoing services with clear service periods and scope notes. This retainer invoice template supports monthly retainers, reserved hours, on-call support, reporting, strategy, and maintenance—ideal for agencies and service providers billing clients for reserved capacity and recurring work. Download instantly in PDF, Word, or Excel format.
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What to Include on a Retainer Invoice
Retainer invoices should make it clear what time period is covered and what the retainer includes.
Retainer details- Service period (month/date range)
- Retainer scope (optional)
- Capacity type (reserved hours or availability)
- Department/cost center (optional)
- Monthly retainer fee
- Reserved hours (if billed this way)
- On-call support
- Reporting/check-ins
- Strategy and planning
- Maintenance and updates
- Subtotal, tax (if applicable), total due
- Payment terms and instructions
Retainer Billing Models: Fixed Monthly Fees and Reserved Capacity
Retainers are structured in a few common ways.
1) Fixed monthly retainer
A flat recurring fee for a defined scope.
2) Reserved hours
A set number of hours reserved each month, billed as a package.
3) Availability/on-call
Clients pay to reserve priority access and response time.
Including a “Retainer scope” field helps clients understand what’s included and what triggers additional billing.
Scope, Overage Work, and Separate Billing
Retainers work best when scope boundaries are clear.
Best practices- Define what work is included in the retainer scope
- Note how overage work is billed (separately or at an hourly rate)
- Keep the service period consistent for recurring invoices
Reporting, Check-Ins, and Retainer Accountability
Clients often want visibility into retainer usage.
Common practices- Monthly reporting and check-ins
- Summary of work performed
- Optional reconciliation of hours used vs reserved