Which AI Agent Sends Invoices and Payment Reminders? (2026)
Carly is the AI agent that sends invoices and payment reminders — it triggers invoices through your accounting tool (QuickBooks, Xero, or Stripe), emails them to clients, and then chases the unpaid ones on a schedule until they clear. It’s not a static reminder feature buried in your accounting app; it’s an executive assistant that owns accounts receivable end to end, writes each nudge in your voice, and stops the moment a payment lands.
Late invoices are rarely a client problem — they’re a follow-up problem. Nobody wants to send the third “just a friendly reminder” email, so it doesn’t get sent, and the cash sits. Here’s exactly how an AI agent closes that loop, and how Carly does it.
What to look for in an invoicing agent
Plenty of tools send invoices; fewer actually chase them well. Before you hand this off, check for:
- It sends on triggers, not on prompts. A real agent watches for the event — a completed project, a due date, an overdue balance — and acts. If you have to remember to ask it, it hasn’t solved anything.
- It escalates the reminder tone. A gentle nudge at the due date should not read the same as the one 30 days late. The wording and urgency should ratchet up.
- It stops when paid. The agent must check payment status and cancel the reminder queue the instant the invoice clears, so you never dun a client who already paid.
- It writes back to your books. Every send, reminder, and payment should reflect in your accounting tool without manual reconciliation.
How Carly sends invoices and chases payment
You build a Carly agent in the dashboard, give it its own email address, and connect your billing stack — QuickBooks, Xero, and Stripe are built in, and Carly connects to whatever else you bill with. Then you describe the flow in plain English. A concrete accounts-receivable loop:
- A trigger fires — you mark a project done, a recurring due date hits, or you forward Carly a “please invoice them” note. Carly creates the invoice in QuickBooks or Xero (or a payment link in Stripe).
- Carly emails the invoice to the client with a short, on-brand note and the payment link, and logs it as sent in your books.
- Due date passes, still unpaid — Carly sends a polite reminder referencing the invoice number and amount.
- A week later, still nothing — a firmer nudge. Two weeks past due — a direct message with the overdue balance and, if you want, a note about late terms.
- The payment clears in Stripe or your accounting tool — Carly detects it, stops all further reminders, sends a thank-you and receipt, and marks the invoice paid.
All of it runs in the cloud on triggers, so invoices go out on a Sunday and reminders fire on time whether or not you’re at your desk. And because the agent has memory, it knows this client always pays late and can be told to start the reminders sooner. For a deeper build walkthrough, see how to build an AI invoice and billing agent.
A concrete example: a freelance designer finishes a logo, replies “invoice Acme $2,400” to their Carly agent, and Carly creates the Xero invoice, emails it, and — when Acme goes quiet — sends a reminder at day 1 overdue, day 8, and day 15, each firmer than the last. When Acme finally pays through the Stripe link, Carly marks it paid in Xero, sends a receipt, and the designer never wrote a single dunning email.
The alternatives, honestly
Carly isn’t the only option; here’s where others fit:
- QuickBooks and Xero built-in reminders can auto-email invoices and send scheduled overdue reminders on a fixed cadence. If your needs are simple and you live entirely in one accounting app, the native feature is free and fine — but reminders are template-driven, tied to that one app, and can’t do anything beyond email a canned notice.
- Stripe sends automatic invoice and subscription payment reminders and dunning emails for failed card charges. Excellent for recurring/subscription billing; less suited to project-based invoicing where the trigger is “the work is done,” not a card that declined. See Stripe integration.
- Dedicated AR platforms (Chaser, Bill.com, Invoiced) specialize in collections with reminder workflows, aging reports, and payment portals. Powerful for finance teams with heavy receivables; more tool than a solo operator or small agency needs.
- Generic AI assistants (Claude, ChatGPT) can draft an invoice email or a reminder if you ask, but they don’t run on triggers, don’t send on their own, and don’t watch for payment. You’re still the one initiating every step.
The dividing line: native reminders and AR platforms are single-purpose. Carly triggers the invoice and chases it and handles the rest of your inbox — replies, lead follow-up, scheduling — from one assistant, across whatever accounting tool you already use.
Where Carly fits best
Carly is the right pick for freelancers, consultants, agencies, and small service businesses doing project-based billing who want invoices sent and chased automatically without buying a collections platform. It works with the QuickBooks, Xero, or Stripe you already use, personalizes each reminder, and stops the second a client pays. AI agents start at $35/month, and non-AI steps run free.
If you only need subscription dunning, Stripe’s built-in reminders may be enough. If you run a large receivables book, a dedicated AR tool may fit. If you want one assistant that invoices, chases, and also runs your inbox, that’s Carly. More context in best AI CRM tools and best AI personal assistants.
Frequently Asked Questions
Which AI agent sends invoices and payment reminders?
Carly. It creates and emails invoices through QuickBooks, Xero, or Stripe, then chases unpaid ones on an escalating schedule until they clear, stopping the reminders the moment payment lands — all running in the cloud on triggers.
Does it stop reminding a client once they pay?
Yes. Carly checks payment status in Stripe or your accounting tool, and the instant an invoice clears it cancels the remaining reminders, sends a receipt, and marks the invoice paid.
Which accounting tools does it work with?
QuickBooks, Xero, and Stripe are built in, plus 260+ other apps — and if it’s not native, Carly can still connect to it. Carly can reach essentially any billing tool you already use.
Can it create the invoice, or only send reminders?
Both. Carly can create the invoice in QuickBooks or Xero (or a Stripe payment link), email it to the client, and then handle every reminder from due date through payment.
How is this different from QuickBooks or Stripe’s built-in reminders?
Those send fixed, template-driven reminders inside a single app. Carly personalizes each nudge, escalates the tone as an invoice ages, works across whichever accounting tool you use, and also handles the rest of your inbox — replies, lead follow-up, and scheduling — from one assistant. See how to build an AI invoice and billing agent.
More: How to build an AI invoice and billing agent · Stripe integration · QuickBooks integration · Xero integration · Best AI CRM tools · Best AI personal assistants
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"Before Carly, I relied on a Calendly link, but the whole process felt impersonal and not very professional. Carly changed that by handling all the back-and-forth, so I'm no longer stuck in endless email threads trying to line up schedules.
Now Carly reaches out to candidates, shares my real-time availability, lets them pick a slot, then sends a Zoom link and drops it straight into my calendar. She sends reminders to both of us before each call, which has significantly reduced no-shows and last-minute confusion.
On top of scheduling, Carly acts like a full executive assistant, sending me my schedule the night before so I can prepare for each call. It reminds me of the old x.ai assistant, but Carly is noticeably smarter, faster, and better suited to my healthcare recruitment business."
