What is a collections letter?

A collections letter is a formal written communication to a customer reminding them of an overdue invoice and requesting payment. Most businesses use a short sequence: a friendly first reminder, a firmer second letter after another cycle has passed, and a final notice before escalation. The cadence is the point. One letter is easy to ignore; a predictable series is harder to dismiss.

The classic letter format states the invoice number and date, the due date, the amount outstanding, and a clear action: pay by date X, contact us, or set up a plan. Good letters avoid legal threats they cannot back up and avoid vague language like as soon as possible. Specific numbers and specific dates produce specific actions.

In a modern AR setup, physical letters are often replaced or supplemented by email and phone follow-ups, but the underlying logic is the same: consistent escalation over a predictable timeline. The medium matters less than the cadence. Customers respond to businesses that follow up reliably, regardless of whether the follow-up arrives as paper, email, or a short phone call.