What is a collection letter?

In business-to-business billing, a collection letter is usually an email or letter from the seller's own finance team, sent after an invoice passes its due date. Its job is to get a specific invoice paid, or to surface the reason it has not been paid, such as a dispute, a missing purchase order reference or an invoice that never reached the right person.

Invoicera is billing operations software. It sends pre-due, on-due and overdue payment reminders from configurable templates on a cadence you set, so the early stages of a collection letter run on schedule. Invoicera is not a debt-collection agency and does not hand accounts to one.

• Sent by: the seller's finance or accounts receivable team.
• About: one or more specific overdue invoices.
• Aim: payment, or the reason payment is held up.
• Not: a letter from a debt-collection agency.

Schedule pre-due, on-due and overdue messages with payment reminders.

Most businesses use three written stages after the due date, sometimes preceded by a courtesy note before it. The timing below is illustrative. Set it from your payment terms and the customer relationship, and stop the sequence as soon as payment or a dispute is recorded.

Track each overdue account through the stages with the collections workflow.

Every stage should let the customer act without searching for anything. Put the facts in the first lines and keep the request specific.

Attach the invoice, or a statement of the account when several invoices are open, so the customer can match your records to theirs.

• Invoice number and date
• Amount due and currency
• Original due date
• Number of days overdue
• How to pay: payment link, portal or bank details
• A named contact for questions or disputes
• The next step and its date

When several invoices are open, attach a billing statement.

A final notice letter tells the customer this is the last written request before the business takes a stated next step. It gives a specific payment date, lists the earlier reminders with their dates and says plainly what will happen if the balance is still unpaid.

Only name a step you are entitled to take under your agreement and intend to take, such as pausing further work, withdrawing credit terms or referring the matter to a legal adviser. Check contractual and legal points with a qualified adviser before sending; a template cannot decide them.

• Labelled clearly as a final notice
• A specific payment deadline
• Dates of the earlier reminders
• The next step, stated factually
• A contact for resolving any dispute before the deadline

Base the due date and days overdue on the agreed net terms.

Keep every stage polite and factual. Firmness comes from specific dates and clear next steps, not from strong language. A customer with a genuine query should find it easy to raise.

Before each letter, check that the invoice was delivered, that no payment is waiting to be matched and that no dispute is open. Keep a record of each letter: date, channel, recipient and wording. That record supports later steps and stops a customer receiving a reminder for an invoice already paid.

• Check payment and dispute status first.
• Send to the agreed billing contact.
• Record the date, channel and wording of each letter.
• Pause the sequence while a dispute is being resolved.

Measure how long customers take to pay with days sales outstanding.

The wording below is a sample, not legal advice. Replace every bracketed detail, adjust the tone to the relationship and check the next step against your agreement.

First reminder (sample). Subject: Invoice [INV-1042] for [$4,800] is now overdue. Hello [name], a quick note that invoice [INV-1042] for [$4,800], due on [15 August 2026], is still showing as unpaid. If it has already been paid, please send the payment reference so we can match it. If not, you can pay using [payment link]. If anything on the invoice needs correcting, reply and tell us which line. Thank you, [your name], [role], [phone].

Final notice (sample). Subject: Final notice: invoice [INV-1042] for [$4,800], [45] days overdue. Dear [name], invoice [INV-1042] for [$4,800] was due on [15 August 2026] and remains unpaid. We wrote to you about it on [date] and [date]. Please pay by [date] using [payment link or bank details], or contact [name] on [phone] before then if there is a problem with the invoice. If we do not receive payment or hear from you by [date], we will [next step permitted by your agreement, such as pausing further work]. Regards, [your name], [role].

Give customers one place to view, download and pay invoices with a client portal.

Invoicera covers the written stages for the invoices it issues. Pre-due, on-due and overdue reminders run as automated sequences with a custom cadence, each stage uses a configurable template, and escalation rules escalate unpaid invoices automatically. On Grow and above, the collections workflow adds statuses and tasks for each overdue account.

AI can suggest reminder wording with tone control; treat it as a draft for your team to review. Invoicera does not act as a collection agency and does not pass accounts to agencies.

• Reminder sequences with a custom cadence
• A configurable template for each stage
• Escalation rules for unpaid invoices
• Collections workflow with statuses and tasks (Grow and above)

Check which plan includes the collections workflow on the pricing page.