How to automate accounts receivable collections

What this automation does

Collections becomes a daily routine that runs itself, and your people only handle the conversations that need a human.

1. Sync open AR. Every morning, the workflow pulls open invoices, balances, due dates and customer contacts from QuickBooks Online, Xero or Stripe.
2. Decide who gets what. A cadence table maps customer segment and days past due to an action, such as a friendly reminder, a firmer follow-up with a statement, a task for the account owner, or a hold flag for operations.
3. Draft the message. For email steps, an LLM drafts a short message that lists the customer’s open invoices, amounts and due dates, includes a payment link, and adjusts tone for the stage and any recent reply.
4. Check, then send. Right before sending, the workflow re-reads each invoice balance and skips anything paid, credited or under dispute. It sends from a real AR mailbox, not a no-reply address.
5. Read the replies. Incoming replies are classified as paid with remittance, promise to pay with a date, dispute with a reason, request for a copy or W-9, wrong contact, or out-of-office. Each category triggers its own next step.
6. Log everything. Each touch, reply and promise is logged against the customer, and summaries appear in HubSpot or your CRM so sales sees what finance sees.

When it is worth building

It pays off when your AR is large enough that following up consistently is a job nobody has time for. Common symptoms are invoices that pass 60 days before anyone notices, a founder chasing payments personally, and customers who reply with questions that sit unanswered for a week.

If you have fewer than 30 open invoices and mostly prompt payers, turn on the reminders in your accounting system and stop there. If most revenue comes from cards on file through Stripe, its own failed-payment retries and emails handle much of the problem. Build the custom workflow when you have a mix of customer types that need different treatment, replies that need routing, or a sales team that needs to know before finance escalates a key account.

Architecture

How to build it

1. Segment customers. Start with three groups, such as key accounts, standard and small balance. Key accounts get owner tasks instead of automated escalation.
2. Write the cadence. For each segment, define the action at a handful of points relative to due date. Keep the first message friendly and include the invoice PDF and a payment link.
3. Write the style guide. A half page on tone, sign-off, what the message may and may not say, and banned content such as fee threats you do not actually enforce.
4. Build the daily run. Pull open AR, apply the cadence, create drafts, run the pre-send balance check, and send. Log every action with the invoice IDs it covered.
5. Build the reply classifier. Watch the AR mailbox. For each reply, extract the label and any dates, amounts or invoice numbers. Promises set a follow-up for the day after the promised date. Disputes pause the sequence and create a task.
6. Add approval for key accounts. For the first month, drafts for key accounts go to a person in Slack or email for one-click send or edit.
7. Report weekly. A short summary of collected amounts, broken promises, open disputes and the oldest balances goes to the owner or controller.

The downloadable starter template below includes the daily AR pull, the cadence lookup, the pre-send balance check and the reply classifier to adapt to your own playbook.

What breaks in production

• Unapplied payments. The customer paid yesterday, but the payment is not applied yet, and they get a reminder anyway. The reply pause and a check against recent bank deposits reduce this, but fast payment application in the ledger is the real fix.
• Wrong contact. Invoices go to the buyer while the customer’s AP department pays. Capture the AP contact from “wrong person” replies and update the customer record.
• Partial payments. The customer short-pays to dispute one line. Treat a balance that drops but does not clear as a signal to ask, not as a reason to escalate.
• Auto-replies. Out-of-office and ticketing system replies get classified as real responses. Detect them by headers and phrasing and ignore them.
• Batched invoices. A customer with twenty open invoices gets twenty emails. Group by customer and send one message per run with a statement attached.
• Deliverability. A sudden jump in outbound email from a new mailbox lands in spam. Warm the mailbox, set up SPF, DKIM and DMARC, and keep daily volume steady.

Timeline and cost

One AR source with email collections typically takes two to three weeks. Lumeor builds it for $4,000 to $10,000, depending on the number of segments, whether reply handling covers disputes with routing to operations, and whether you want CRM sync. Model usage is small, roughly one draft per customer per step plus one call per reply. For a sense of ongoing model and hosting spend, see what it costs to run an AI agent each month. If your AR mailbox also receives vendor mail, support questions and spam, the shared inbox triage guide covers the broader classifier. Promise-to-pay data feeds directly into an AI-assisted cash flow forecast.

How to measure success

• Days sales outstanding (DSO), measured monthly
• Share of AR more than 60 and 90 days past due
• Promise-to-pay kept rate, by segment
• Replies handled without a person touching them
• Median days to resolve a dispute once flagged
• Hours per week spent on collections by finance staff