Prepare a retainer invoice the client can check

A worked included-hours example

Illustrative example, not customer data: an agency has agreed a $1,200 monthly base fee for 10 included hours, with approved additional work billed at $100 per hour. During the example period it approves 12 hours: 8.5 hours of maintenance and 3.5 hours of revisions. Approved usage is 12 hours, so the overage is 2 hours and the extra fee is $200.

Work summary: maintenance 8.5 hours; revisions 3.5 hours; total approved usage 12 hours. Included hours are covered by the base fee and are not charged again as a separate hourly line. This example shows no tax calculation and is not a legally compliant invoice template for every jurisdiction.

Check the calculation before sharing

Overage hours = the greater of zero and approved usage minus included hours. Overage amount = overage hours multiplied by the agreed rate. Base plus overage = the period subtotal before any other applicable adjustment.

In this example: 12 minus 10 = 2 hours; 2 multiplied by $100 = $200; $1,200 plus $200 = $1,400. If only 8.5 hours were used against a ten-hour allowance, the overage would be zero. With a flat-fee retainer that has no hour cap, an hour-based overage is not implied; changes need to follow the client agreement. Read about choosing a retainer model.

Copy this monthly invoice outline

Illustrative invoice outline, replace every placeholder:
Agency name and contact details: [your agency]
Client and billing details: [your client]
Invoice reference and issue date: [reference and date]
Service period: [start date to end date]
Retainer description and agreed scope: [description]
Base fee and included hours, if applicable: [fee and allowance]
Approved hours used this period: [hours]
Overage hours and agreed rate: [hours and rate]
Overage authorization reference, if applicable: [reference]
Base plus overage subtotal: [amount]
Applicable tax or adjustments, checked separately: [details]
Invoice total and currency: [total and currency]
Due date and externally agreed payment instructions: [details]
Work summary or agreed supporting record: [summary]

Review these items each month

• Check the invoice dates against the agreed service period.
• Reconcile the approved work summary to the usage total.
• Check that the base fee covers the included hours only once.
• Verify the rate and any required authorization for extra work.
• Exclude work already billed elsewhere and resolve duplicates.
• Follow the agreement for unused hours; do not assume rollover.
• Review currency, tax details, due date and external payment instructions.
• Check the shareable invoice/PDF before sending it to the client.

Using this workflow in ABH

On Pro, an Owner can use retainer periods to review a base fee, included hours and calculated overage from approved time on that client's projects. The Owner generates a draft period invoice and checks it before sharing. ABH does not collect the client payment or automatically enforce your contract terms. Clients pay you externally, and an Owner can record the receipt manually.

Free includes time tracking and ordinary invoices within its limits. Retainer management is a Pro feature, so starting on Free is not a retainer trial. For hourly work, use the ordinary time invoicing guide and check current plan details.

From setup to the monthly client report

Before the first period, confirm the fee, allowance, service dates and external authorization process. Use the monthly retainer review to report approved usage and unused capacity without promising rollover. The overage approval guide separates client authorization from internal time approval.

Additional illustrative worked example, USD, excluding taxes: a fictional studio has a $1,200 monthly fee for 12 included hours and an agreed $110 overage rate. It reviews 13 approved eligible hours in the same period. With external written authorization for the extra hour, overage is 13 minus 12, or 1 hour, billed at $110. The draft total is $1,310. Two separately logged internal hours are non-billable and excluded from usage.

Keep rollover and receipts explicit

If the agreement permits unused hours to carry forward, reconcile that decision externally with the originating period and any expiry. Do not treat it as an automatic ABH rollover bank. The Owner manually generates the period invoice after reviewing usage and previous billing. A generated invoice does not mean client money was collected.

Free includes 1 client, 1 project, 20 tracked hours per month, 3 invoices per month and 1 user, with an invoice watermark. Retainer management requires Pro. Review current pricing, start free for ordinary invoicing, or use the alternatives hub to compare workflow boundaries.