Nobody knows how many hours are left
When the hours bank lives in a spreadsheet, the account manager finds out the retainer is used up after the team has already done the extra work.
Retainer billing for agencies
The best retainer billing software for agencies handles the three places agency retainers go wrong: the hours run out unnoticed, the monthly invoice goes out late, and the client forgets to pay. In Workspace369, each retainer holds a balance that draws down as work is billed, your team's time entries show how much of the hours bank is left, recurring invoices go out on their own schedule, and clients who agree to card autopay are charged on the plan's invoice dates. Retainers, recurring invoices and card autopay are on every plan, from $29/mo; a 5-person agency pays $104/mo on Voyager. Clients can pay by card or ACH bank transfer on every plan. The native app for iPhone and iPad, with iPad in every orientation, opens the same workspace.
14-day free trial. Card required. After the trial: from $29/month. Renews automatically every month until you cancel. Cancel anytime in Settings → Billing.

Key facts
Retainer billing for agencies at Workspace369 covers 10 areas, including retainer balances that draw down, hours bank on time entries, recurring invoice plans.
The workflow runs in 4 steps, from "create the retainer on the client record" to "collect by autopay, with consent".
Workspace369 starts at $29/mo for 1 seat, and the Commander plan includes 20 seats and 12× Cadet usage at $299/mo.
Additional seats cost $10 each; full pricing is public on the Workspace369 pricing page.
The problem
When the hours bank lives in a spreadsheet, the account manager finds out the retainer is used up after the team has already done the extra work.
Copying last month's invoice, changing the date and sending it by hand is easy to put off until the client's payment arrives a week later than it should.
Without autopay the client has to act every month, so a busy client pays two weeks late and someone on your team has to follow up.
The product
Send quotes, bill milestones or retainers, and let automated reminders chase anything outstanding.

Email, SMS, calls, and voicemail land beside the client record — with AI summaries, so anyone on the team can reply with full context.

Tasks, files, and status for every engagement — visible to the team and, through the client portal, to the client.

Clients watch progress, files, and invoices in a branded portal instead of asking your team for updates.

Workflow
The retainer holds the client's prepaid balance. It draws down as work is billed against it, and a prepaid balance can be refunded from the same record.
Everyone on the team tracks time with timers or timesheets. Time entries show the hours bank, so the account manager sees what is left before agreeing to more work.
A recurring invoice plan sends the monthly retainer, hosting or maintenance invoice on its schedule, and billable time can become an invoice without retyping.
Clients agree to card autopay and manage it from a secure page. They get a notice 3 days before every automatic charge, or 7 days before on yearly plans.
Product coverage
Team pricing
$74 / month
Founding offer: $444 for your first year, billed yearly
2 seats included
Start Voyager trial14-day free trial. Card required. After the trial: $74/month for Voyager. Renews automatically every month until you cancel. Cancel anytime in Settings → Billing.
$149 / month
Founding offer: $894 for your first year, billed yearly
10 seats included
Start Specialist trial14-day free trial. Card required. After the trial: $149/month for Specialist. Renews automatically every month until you cancel. Cancel anytime in Settings → Billing.
$299 / month
Founding offer: $1,794 for your first year, billed yearly
20 seats included
Start Commander trial14-day free trial. Card required. After the trial: $299/month for Commander. Renews automatically every month until you cancel. Cancel anytime in Settings → Billing.
Founding member offer on yearly plans: your first year costs the same as 6 months, for the first 100 customers who join by Oct 31. USD monthly billing. Compare all plans. Prefer a guided walkthrough first? Book a demo.
Switch & Save
Our team sets up your workspace with you and helps move your clients and invoices from the tools you use now.
Export your data as a spreadsheet and AI Import maps the columns for you. Support can help with anything unusual.
Offer ends .
14 days free · card required · then $29/mo · cancel anytime
After signup, claim free setup in your workspace.
Selected App Store reviews
SMB ModernizationGreat tool for modernizing small businesses. Ability to leverage AI without technical background.
True all-in-one systemIt beautifully combined my CRM, team calendar, and billing tools so I could finally stop paying for a bunch of separate software subscriptions
Best app for my construction businessGreat app. This app solved all my needs! Not only did it help, but it is cheaper than other apps. I highly recommend this app if you want to start organizing and automating your business on another level. Also love the design
Quoted exactly as written, in the reviewer’s own language. This is a selection of reviews, not all of them. Reviews from our own team are left out of the selection, but the overall rating includes their ratings.
Get started
14-day free trial. Card required. After the trial: from $29/month. Renews automatically every month until you cancel. Cancel anytime in Settings → Billing.
FAQ
The best retainer billing software for agencies has four things: a retainer balance that draws down as work is billed, an hours bank the whole team's time feeds, invoices that repeat on their own, and card autopay the client agrees to. Workspace369 does all four on every plan, and a team of up to 10 pays $149 a month on Specialist. One limit to know: credit notes are not available yet.
Retainer billing software tracks money a client pays in advance and bills ongoing work on a schedule. For an agency it also needs to show the team's hours against the retainer. In Workspace369 a retainer holds a balance that draws down, time entries show the hours bank, recurring invoices repeat on a schedule and card autopay runs with the client's consent.
Retainers and payment schedules, recurring invoices and saved payment methods are on every plan, starting with Cadet at $29 a month for one person. Agencies usually start on Voyager ($74 a month, 2 seats) or Specialist ($149 a month, 10 seats); extra seats are $10 a month each.
Yes, after the client agrees to card autopay. The card is then charged on the invoice dates in the plan, and the client gets a notice 3 days before every automatic charge (7 days before on yearly plans). Clients can manage autopay from a secure page.
Log the team's work as time entries against the client. The entries show the hours bank, so you can see what is left before the month ends and decide whether extra work needs a new quote.
Bill it separately: turn the extra billable time into an invoice, or send a proposal for the new scope. From Specialist, a change order records the added work and its price and the client approves it by link.
Ready when you are
Start with the modules you need today, then turn on AI, automations, accounting, inventory, requests, and reporting as the operation grows.
14-day free trial. Card required. After the trial: from $29/month. Renews automatically every month until you cancel. Cancel anytime in Settings → Billing.