How to Build an AI Invoice & Billing Agent

How to Build an AI Invoice & Billing Agent

An AI agent that creates invoices, chases late payments, reconciles accounts, and gives you a cash flow snapshot — all through email.

When a payment lands, the agent posts to Slack:

# billing-alerts
B
Billing Agent 2:17 PM
Payment received: Morales — Contract Review
Invoice
#2036 — $3,500.00
Status
Matched to Stripe payment, QuickBooks marked paid, receipt sent
AR Impact
Outstanding balance down to $37,825

How it works

Create a billing agent at dashboard.carlyassistant.com. Connect your accounting software, payment processor, and email — QuickBooks, Stripe, and Gmail cover most setups. The agent creates invoices, sends reminders on a schedule you define, matches incoming payments, and delivers AR reports on demand. Full walkthrough: How to Create a Custom AI Email Agent.


What an AI invoice agent connects to

Accounting: QuickBooks, Xero, FreshBooks, Zoho Books, Zoho Invoice, Zoho Inventory, Moneybird, sevDesk, FreeAgent

Payments: Stripe, Square, Flutterwave, Lemon Squeezy

Email: Gmail, Outlook

Messaging: Slack, Microsoft Teams

Spreadsheets: Google Sheets, Microsoft Excel, Airtable

Storage: Google Drive, Dropbox, Box, SharePoint

See the full list of integrations.


What an AI billing agent can do

  • Bill a client when a matter closes — tell the agent the matter, hours, and rate; it builds the invoice in QuickBooks with itemized time entries, emails it with a payment link, and tracks it through to payment
  • Chase retainer replenishments automatically — the agent monitors retainer balances and sends escalating reminders when they drop below threshold, so no work starts on an empty trust account
  • Run monthly trust account reconciliation — the agent cross-references IOLTA deposits against open matters, flags discrepancies, and delivers a summary you can hand to your bookkeeper

Build your billing agent in under 10 minutes at dashboard.carlyassistant.com, or email carly@usecarly.com and describe the agent you need.

Related: How to Build an AI Bookkeeper | How to Create a Custom AI Email Agent | Best AI Tools for Solopreneurs | How to Build AI Employees

Ready to automate your busywork?

Carly schedules, researches, and briefs you—so you can focus on what matters.

Get Carly Today →

Or try our Free Group Scheduling Tool or Free Booking Page