Past Due Invoice: What to Send, When, and When to Stop

A past-due invoice is an invoice whose stated payment date has passed without a recorded payment. Before sending a reminder, verify that the invoice arrived, the balance is still correct, and no question or payment is waiting to be reconciled.

Late payment can come from an overlooked email, an approval delay, cash timing, a disputed line or incorrect payment instructions. A fixed reminder sequence keeps the message factual while each reply is routed to the right next step.

01

When is an invoice officially past due?

For an ordinary invoice, follow the due date and payment terms shown on the invoice or in the underlying agreement. A Net 30 invoice, for example, becomes past due after its stated 30-day payment period passes—not because every invoice follows the same universal timetable.

If the invoice has no due date, check the agreement and the rules that apply to the transaction before describing it as late. _Past due_ and _overdue_ are commonly used for the same practical status: the agreed payment date has passed.

02

Before you send anything: verify the record

  • Did the invoice arrive? Check the address, delivery status and whether the client requires a particular accounts-payable inbox or portal.
  • Is the balance current? Reconcile credits, deposits, partial payments and approved adjustments before quoting an amount.
  • Is anything on it disputed? If the customer has questioned a line, chasing the total makes it worse. Resolve the line first.
  • Are the original terms clear? Confirm the due date, invoice number and any PO or job reference the client needs to match it.
  • Can the client act on the message? Include the current invoice and the payment instructions or contact route they actually need.
03

An adaptable day 1, day 15 and day 30 sequence

The timings below are examples, not a universal legal schedule. Adapt them to the agreement, the client relationship and any local requirements. Each message should carry the invoice and one clear request.

TimingPurposeWhat to includeExample wording
Day 1 after the stated due dateConfirm receiptInvoice number, balance, due date, attached copyJust a reminder that invoice #214 for $860 was due on 14 August. I have attached a copy—please let me know if anything is holding it up.
Around day 15Request a payment date or issueCurrent balance, payment route, direct questionInvoice #214 remains open at $860. Could you confirm the scheduled payment date, or tell me what needs resolving?
Around day 30State the agreed next stepRecord of prior contact and only consequences already agreed or otherwise applicableInvoice #214 is still unpaid. Please reply by 16 September so we can confirm payment or resolve an outstanding issue.
04

If the client says the job isn't finished

Do not keep sending the same reminder. First identify what the invoice was meant to bill: completed work, delivered materials, an approved deposit, or an agreed progress stage. Send the supporting scope, visit record or progress calculation and ask the client to identify the disputed part.

If only one line is disputed, separate that issue from the undisputed balance when the agreement and your process allow it. If the invoice was raised too early, correct the document and preserve the change trail instead of trying to explain a premature total by email.

05

Route the reply instead of continuing the sequence

A reminder sequence is useful only while no new fact has changed the workflow. Stop the scheduled message and record the next action when any of these events occurs:

  • Payment arrived. Reconcile it and stop every pending reminder.
  • A line is disputed. Pause the sequence and route the question to resolution.
  • A partial payment arrived. Acknowledge it and update the message to the remaining balance.
  • The client promised a payment date. Record the date and wait until it passes before deciding whether to resume.
  • The email bounced or the contact changed. Stop sending to the failed address and verify a valid business channel.
06

When reminders are no longer the right tool

If the client remains silent after the documented sequence, decide whether to pause future work, negotiate a payment plan, write off the balance or seek formal recovery. That is a business and, sometimes, legal decision—not a wording problem. Preserve the invoice, agreement, delivery or work records, payment history and reminder log, then obtain appropriate advice before taking a step you have not already agreed with the client.

Frequently asked questions

Is past due the same as overdue?

In ordinary invoicing, both terms usually describe an invoice whose agreed payment date has passed. Use the wording your agreement or accounts process uses.

Can I add a late fee after the invoice is overdue?

Do not introduce a fee only in the reminder. Apply a late fee only when it was properly agreed and is permitted for the transaction; check the agreement and applicable rules.

What if the customer disputes only one line?

Pause the generic reminder, identify the disputed line, and provide the supporting record. Keep the disputed and undisputed amounts clear rather than repeatedly demanding an unexplained total.

How do I follow up after a partial payment?

Acknowledge the payment, show the date and amount received, and follow up only on the updated balance. Attach a corrected statement or invoice record when your process requires it.

How often should I send invoice reminders?

Use a consistent schedule that fits the agreed terms and relationship. Day 1, 15 and 30 are examples; stop or reroute the sequence as soon as payment, a dispute, a promised date or a delivery failure changes the situation.

Writing these emails by hand every time is the part that wears people down. Invosmith Pro includes automatic, polite follow-ups that stop the moment an invoice is paid, disputed or answered — see Pro pricing for availability.

A chase only works if the invoice underneath it was clear. Here are free invoice templates by industry you can download.