AgentCollect follows up with the customer accounts your team does not have time to reach, by voice, email and SMS. Agents work under your brand, and your customers pay you directly.
TL;DR
- Most late invoices do not need an agency. They need a schedule, an owner per step and a written record.
- Automate the early, routine steps. Keep judgment (payment plans, disputes, write-offs, legal steps) with a person.
- Stop every reminder the moment an invoice is paid or disputed.
- Use the letters below as the tools inside the schedule: Letter 1 for the friendly reminder, Letter 2 for the formal notice, Letter 3 for the final demand.
How to collect unpaid invoices without hiring collectors
You do not need a collections team or an agency to work most late invoices. You need a schedule, a clear owner for each step, and a record of every contact.
Rex, which sells AI accounts receivable software, puts the same idea in one line: "To build a collections workflow from scratch, define three things: the stages an invoice moves through, the triggers that move it between them, and the owner responsible at each stage." (Rex, How to build a collections workflow, checked October 2026)
The schedule, step by step
Adjust the day counts to your own payment terms. The steps assume net 30.
- Put the terms in writing before you invoice. Payment terms, due date, accepted payment methods and any late fee your contract allows. Owner: finance.
- Remind before the due date. A short, friendly note with the invoice attached and a way to pay. Owner: automated.
- Friendly reminder soon after the due date. Use Letter 1. Invoice number, amount, due date, how to pay, and an offer to resend the invoice. Owner: automated.
- Call or text if there is no reply. Confirm the invoice reached the right person and ask what is in the way. Often it is a missing invoice copy, a wrong PO number or an unclear line item. Owner: your AR team, or an AI agent working under your brand.
- Formal notice around 30 to 45 days late. Use Letter 2. Refer to the earlier reminder, ask for payment, a written payment plan or the reason for any dispute by a set date. Link the payment plan agreement if cash flow is the issue. Owner: AR lead.
- Final demand around 60 days late. Use Letter 3. List every prior contact, set a hard deadline and name only the next steps you will actually take. See the demand letter templates for a formal version. Owner: finance lead.
- Decide what happens after the deadline. A person chooses between a payment plan, small claims, a third-party agency, a demand on attorney letterhead or a write-off. This is a judgment call, not an automated step. Owner: finance lead or owner.
- Log every contact and stop when paid. Date, channel, who you reached and what they said. Pause or stop reminders the moment an invoice is paid or disputed. Owner: whoever sends the message, or your system.
Published schedules from other vendors land in the same range. Rex's blueprint for net 30 terms moves an invoice to a firmer notice at 20 days past due, a final notice at 45 days and a handoff at 60 days (Rex, checked October 2026). SOPCompass's invoicing and collections procedure sends a friendly reminder 3 days before the due date and escalates accounts at 30 days past due (SOPCompass, updated September 17, 2026). ti3 recommends a defined Day 1, Day 7, Day 14 and Day 30 sequence and a hard deadline of 10 business days on the final letter (ti3, small business AR recovery guide, checked October 2026).
Automate the routine, keep the judgment
ChaseBot's rule is a good one to keep on the wall: "automate the process, keep the judgment manual." (ChaseBot, checked October 2026) The same guide calls the ability to stop instantly when a client pays the most critical feature in collections automation.
In practice that means:
| Step | Automate it | Keep it with a person |
|---|---|---|
| Pre-due and first reminders | Yes | No |
| Invoice copies, PO questions, payment links | Yes | Only if something is wrong on the invoice |
| Calls and texts to accounts nobody has time to reach | Yes, with a clear record | Large or sensitive accounts |
| Payment plans, credits, discounts, reissued invoices | No | Yes |
| Disputes | Pause the reminders | Yes, decide the outcome |
| Final demand and what happens after it | Send on schedule | Yes, choose the next step |
Why customers pay late
AgentCollect's view: customers often pay late because of friction, such as a missing invoice copy, a wrong PO number or an unclear invoice, not because they refuse to pay. That is why step 4 is a conversation, not a firmer letter. The fastest fix is often a resent invoice or a corrected PO number.
Three ways to run the schedule
ti3 frames the choice as three paths: "handle it yourself, use collection software, or hire a collection agency." (ti3, checked October 2026)
Your own team, by hand. Works when you have a few dozen open invoices and someone who owns the list every week. The cost is time, and the long tail of small invoices is usually what slips.
Reminder software plus your team. Automated emails and payment links handle steps 2, 3 and 8. Your team still makes the calls in step 4 and owns steps 5 to 7.
An AI agent working under your brand. The agent handles the routine contact in steps 2 to 4 by email, text and voice, and your team keeps the decisions in steps 5 to 7. AgentCollect is one option of this kind. Ask any vendor of this kind who owns each decision, how a dispute reaches your team, and whether its AI can ever change what a customer owes.
A third-party agency is a different model: the account leaves your hands and the agency contacts your customer in its own name. Use it when you have decided, as a business, that the relationship is over.
When to send each letter
| Letter | When to send | Channel | Tone | Goal |
|---|---|---|---|---|
| 1. Friendly reminder | Soon after the due date (about 7 to 14 days late) | Warm, helpful | Get the invoice in front of the right person | |
| 2. Formal notice | About 30 to 45 days late | Email, plus certified mail | Professional, firm | Ask for payment, a written plan or the dispute reason by a date |
| 3. Final demand | About 60 days late | Certified mail, plus email | Serious, direct | Last request before the next step you have chosen |
All names, amounts and dates in the letters are sample values. Replace them with your own.
Letter 1: friendly payment reminder (about 7 to 14 days late)
Send via: email
Subject: Quick reminder: Invoice #[INV-0847] is past due
Dear [Sarah],
I hope you are well. I am writing about Invoice #[INV-0847] for [$4,750.00], which was due on [February 15] under our [Net 30] terms.
Our records show we have not received payment yet. Invoices sometimes get lost in an inbox, so I wanted to make sure this one reached you.
Payment details:
- Invoice number: [INV-0847]
- Amount due: [$4,750.00]
- Due date: [February 15]
- Days past due: [10]
- Ways to pay: [ACH transfer, check or card, with your payment link]
If you have already paid, please ignore this note, and thank you. If anything on the invoice looks wrong, or you need a copy or a different PO number on it, reply and I will fix it today.
We value working with [your company name] and look forward to continuing.
Best regards,
[James Mitchell]
Accounts Receivable, [Acme Corp]
[email] | [phone]
Tips
- Use the contact's first name.
- Quote the invoice number and amount.
- Assume they missed it.
- Offer more than one way to pay.
- Offer to resend or correct the invoice. It removes the most common reason for delay.
Letter 2: formal notice (about 30 to 45 days late)
Send via: email, plus certified mail
Subject: Formal notice: Invoice #[INV-0847] is now [35] days past due
Dear [Sarah],
This letter is a formal notice about the open balance on your account with [Acme Corp].
We sent a reminder on [February 25]. Invoice #[INV-0847] for [$4,750.00] is still open and is now [35] days past due.
Account summary:
- Invoice number: [INV-0847]
- Amount: [$4,750.00]
- Due date: [February 15]
- Days past due: [35]
- Previous reminder: [February 25]
Within [10] business days of this notice, please send one of the following:
- Payment of [$4,750.00]
- A written payment plan proposal, if cash flow is the issue
- The reason for any dispute about the invoice or the work delivered
[Only if your agreement says so: Under our service agreement, balances more than [45] days past due may carry a late fee of [rate] and services may be paused until the balance is cleared.]
We would like to settle this directly with you. Please reply or call me to agree on next steps.
Sincerely,
[James Mitchell]
Director, Accounts Receivable, [Acme Corp]
[email] | [phone]
Tips
- Refer to the earlier reminder to build a paper trail.
- Offer a payment plan. It shows flexibility.
- Mention late fees or a service pause only if your contract allows them.
- Give a clear response date.
- Leave the door open for a dispute.
Letter 3: final demand (about 60 days late)
Send via: certified mail, plus email
Subject: Final demand: payment required for Invoice #[INV-0847]
Dear [Sarah],
This letter is a final demand for payment of the open balance owed to [Acme Corp].
Invoice #[INV-0847] for [$4,750.00] is now [65] days past due. We wrote to you on [February 25] and again on [March 20] and have not received payment or a reply.
Balance:
- Invoice number: [INV-0847]
- Principal: [$4,750.00]
- Late fee [only if your agreement provides one]: [amount]
- Total due: [total]
- Payment deadline: within [10] calendar days of this letter
If we do not receive payment or a reply by that date, we will take the following step without further notice: [name only the step you will actually take, for example: refer the account to a third-party collection agency, or pursue the remedies our service agreement and applicable law allow].
We would still prefer to settle this directly. If something is preventing payment, call me at [phone] before the deadline to discuss options.
This letter is sent by certified mail, return receipt requested, and by email.
Sincerely,
[James Mitchell]
Director, Accounts Receivable, [Acme Corp]
[email] | [phone]
Tips
- List every prior contact with dates.
- Show any late fee separately from the principal.
- Name one concrete next step, and only one you will take.
- Use a hard deadline in calendar days.
- Send by certified mail for proof of delivery.
Legal notes
- Consumer accounts follow different rules. These letters are written for invoices one business sends another. The US Consumer Financial Protection Bureau explains that the Fair Debt Collection Practices Act covers debts "primarily for personal, family, or household purposes," does not cover business debts, and does not generally cover collection by the original creditor (CFPB, checked October 2026). State rules can still apply, so check yours, and talk to counsel before writing to consumers.
- Never threaten a step you will not take. Do not misstate the amount owed or who you are.
- Keep everything. Copies of every letter, delivery confirmations and replies.
- Ask a lawyer for large or complex balances before you send a final demand.
Where AgentCollect fits
We help companies get paid sooner, with an AI billing concierge on every customer account.
AgentCollect is not a collection agency. AgentCollect is software with a dedicated AI agent per account, working under the client's brand, and the client keeps the customer relationship.
- AgentCollect follows up with the customer accounts your team does not have time to reach, by voice, email and SMS.
- AgentCollect answers your customers the moment they ask: invoice copies sent during the call, PO questions, in their own language.
- Your AgentCollect agent can introduce itself as your billing assistant, not as a collector.
- With AgentCollect, when a customer disputes, calls on that account stop and the dispute can be routed to your team.
- With AgentCollect, your team keeps every decision that needs judgment. The AI never applies a credit, discount or invoice reissue on its own. Those requests go to your team.
- When the AgentCollect agent is not sure, it flags the case to your team in the AgentCollect dashboard or in Slack.
- AgentCollect offers a VIP do-not-contact list and pause or stop at invoice level.
- AgentCollect offers attorney mode for larger balances: formal demand letters.
- AgentCollect starts from your open invoices, through a connection to your billing system or a spreadsheet upload.
- AgentCollect does not buy your receivables. Your customers pay you directly.
Talk to us | How it works | In-house team or an AI agent?
FAQ
How do I collect unpaid invoices without hiring collectors?
Run a fixed schedule in your own company's name: a reminder before the due date, a friendly reminder soon after it, a call or text if there is no reply, a formal notice around 30 to 45 days late and a final demand around 60 days late. Give each step one owner and log every contact. Automate the routine steps and keep payment plans, disputes and legal steps with a person.
When should I send a collection letter?
Send a friendly reminder soon after the due date, about 7 to 14 days late. Send a formal notice about 30 to 45 days late and a final demand about 60 days late. Adjust the days to your payment terms.
Is a collection letter legally binding?
No. A collection letter is not a contract or a court document. It is a written record that you asked for payment, and a final demand sent by certified mail is useful proof if you take a further step later.
Should I send collection letters by email or by mail?
Email works for reminders. For the formal notice and the final demand, send both email and certified mail, so you have proof of delivery.
Is AgentCollect a collection agency?
No. AgentCollect is not a collection agency. AgentCollect is software with a dedicated AI agent per account, working under the client's brand, and the client keeps the customer relationship. AgentCollect does not buy your receivables. Your customers pay you directly.
Will AgentCollect sue my customers or report them to a credit bureau?
No. AgentCollect states: "We do not file lawsuits or take debtors to court. Legal outreach is limited to demand letters, not litigation." AgentCollect also states: "We do not report debtors to any credit bureau."
Can we start without connecting our ERP?
Yes. You can start without connecting your ERP: AgentCollect can work from a spreadsheet upload and connect to your billing system later.
Related templates
Sources
- Rex, "How to build a collections workflow", https://www.rex.inc/resources/guides/how-to-build-a-collections-workflow (checked 2026-10-14)
- SOPCompass, "Invoicing and collections SOP", updated September 17, 2026, https://sopcompass.com/templates/invoicing-and-collections-sop (checked 2026-10-14)
- ChaseBot, "Automate collections process", https://chasebot.co/blog/automate-collections-process (checked 2026-10-14)
- ti3, "Small business collections without a lawyer", https://ti3.co/blog/small-business-collections-without-lawyer/ (checked 2026-10-14)
- ti3, "Small business AR recovery: complete guide", https://ti3.co/blog/small-business-ar-recovery-complete-guide/ (checked 2026-10-14)
- Consumer Financial Protection Bureau, "What laws limit what debt collectors can say or do?", https://www.consumerfinance.gov/ask-cfpb/what-laws-limit-what-debt-collectors-can-say-or-do-en-329/ (checked 2026-10-14)
Disclosure: this page is published by AgentCollect, which sells one of the options described above.