Monthly retainers — 2026
One retainer invoice per client per month, grouped by client, with tier, billing period, and status.
Templates · Bookkeeping retainers
An invoice tracker template for independent bookkeepers
Most of your billing is a steady monthly retainer per client, but the messy part is the exceptions: a new client's catch-up cleanup, a quarter with double the transaction volume, or a client whose tier changed mid-year. When one client's June retainer slips unbilled, it's easy to miss until July. This template gives you one workspace to record each client's retainer invoice per month, with tier, billing period, and status, plus the engagement letter attached.
The problem
Why retainer invoices get missed
Recurring invoices feel automatic until one doesn't go out. Mixing standard retainers with one-off cleanup work and tier changes makes a flat list hard to reconcile.
- A client's monthly retainer simply never got invoiced for one period and nobody caught it until the next close.
- A catch-up cleanup project blurs into the regular retainer, so the one-off scope and fee get lost.
- A client moved from the basic tier to a higher tier mid-year and old invoices still show the old amount.
- A high-volume month wasn't noted, so the extra transaction work went unbilled.
- The engagement letter that defines scope and fee isn't filed where the invoices are.
The workflow
Bill every retainer, every period
Record one invoice per client per billing period, keep the tier visible, and separate one-off cleanup work.
- 1
Set each client's tier
Note the retainer tier (basic, standard, full-service) and its monthly fee on the client record so invoices stay consistent.
- 2
Invoice per period
Each month record one retainer invoice per client with the billing period (e.g. June 2026), the tier, and the amount.
- 3
Separate cleanup work
Record catch-up and cleanup engagements as their own one-off invoices, with a transaction-volume note, so they don't blur into the retainer.
- 4
Set a status
Mark each invoice sent, paid, or overdue and update it as payment arrives.
- 5
Reconcile at month close
At month-end, check that every active client has a retainer invoice for the period so none slips.
Record structure
What to record for each bookkeeping invoice
These fields keep steady retainers and exception work both reconcilable per client.
- Client
- The business this invoice is for, kept as a consistent client record.
- Billing period
- The month or quarter the invoice covers, e.g. June 2026, so recurring bills don't double up or skip.
- Retainer tier
- Basic, standard, or full-service, with the agreed monthly fee.
- Catch-up / cleanup line
- Whether this is a one-off cleanup or catch-up engagement rather than the standard retainer.
- Transaction-volume note
- A note when volume was unusually high, explaining any extra charge for the period.
- Amount
- The invoice total and currency for the period.
- Status
- Sent, paid, or overdue, updated as payment lands.
- Attached engagement letter
- The signed engagement letter filed on the client record so scope and fee are always at hand.
Example setup
An example folder setup
One way to organize retainer billing inside your workspace.
Catch-up & cleanup jobs
One-off cleanup and catch-up engagements with their transaction-volume note and scope.
Engagement letters
Each client's signed engagement letter defining tier, scope, and fee.
Tier-change notes
A short note per client recording when a tier changed and the new fee, so invoices stay correct.
Common mistakes
Mistakes to avoid
- Assuming recurring invoices go out on their own and not checking that each period was billed.
- Folding catch-up cleanup work into the regular retainer, so the one-off scope and fee disappear.
- Leaving old invoice amounts after a client moved up a tier.
- Not noting a high-volume month, so the extra work goes unbilled.
- Keeping the engagement letter somewhere other than where the client's invoices live.
How it helps
How Cash Workspace helps
One invoice per period
Record each client's retainer per billing period so a skipped month is obvious at close.
Tier and one-off side by side
Keep the retainer tier visible and record cleanup work as its own invoice so scope never blurs.
Engagement letters attached
Attach each client's engagement letter to their record so scope and agreed fee are always one click away.
Related
Related templates and checklists
Retainer payment tracker
Keep recurring monthly payments reconciled per client.
Consultant invoice tracker
Track per-engagement invoices in the same structured way.
Monthly finance close checklist
Close each month cleanly with every client billed.
Accountant document checklist
Know what records to keep ready for handoff.
All finance workflows
Browse the full Cash Workspace workflow library.
FAQ
Bookkeeper retainer invoice FAQ
- How do I make sure every client's retainer gets invoiced each month?
- Record one retainer invoice per client per billing period, then at month close check that every active client has an invoice for that period. A missing one stands out immediately.
- How do I handle a one-off catch-up or cleanup project?
- Record it as its own invoice rather than folding it into the retainer, and add a transaction-volume note explaining the scope. That keeps the special engagement separate and clear.
- Where does the engagement letter go?
- Attach it to the client's record so the agreed tier, scope, and fee sit alongside every invoice you raise for that client.
Organizing help — not tax, accounting, or legal guidance
Cash Workspace is a free workspace for organizing invoices, expenses, receipts, clients, and documents. This page is organizing guidance only — not tax, accounting, legal, or bookkeeping guidance. Cash Workspace does not connect to your bank, does not scan or read your receipts for you, and does not move or collect payments. Whether an expense is deductible depends on your situation, so confirm it with a qualified accountant or tax professional.
Bill every retainer, every period
Start a free workspace and record each client's retainer per month with its tier and status so no period slips and no cleanup job goes unbilled.