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Unusually Overdue Invoice Outside Normal Behaviour

Marsha Galicia avatar
Written by Marsha Galicia
Updated yesterday

XBert Type: Standard

Accounting Software: Xero, MYOB, QuickBooks

Country Restriction: All regions

Risk Type: Overdue Risk

Business Function: Sales

Overview

The "Unusually Overdue Invoice Outside Normal Behaviour" XBert identifies invoices that are significantly more overdue than your historical norms for similar-sized invoices. This alert helps prioritise follow-up with customers whose late payments may be at greater risk of turning into bad debts.

What it does

This XBert uses a statistical outlier method to compare your current unpaid invoices to historical paid invoice behaviour. It highlights invoices that are more overdue than expected based on the invoice amount, helping you act on unusually delayed payments before they become critical.

How it works

XBert does the following:

  • Groups historical Paid invoices into 5 equal-sized bins based on the total amount of each invoice.

  • Calculates the cutoff overdue days for each bin using the interquartile range (IQR) method (Q3 + 1.5 × IQR).

  • Applies these cutoff thresholds to current unpaid invoices that are at least 7 days overdue.

  • If an unpaid invoice exceeds the calculated cutoff for its amount bin, XBert raises an alert.

For example, if invoices between $100–$900 are typically paid within 28 days, an unpaid invoice in this range that’s 40+ days overdue may be flagged as unusually late.

Example/Use Case

A client, “ABC Supplies,” has an unpaid invoice of $467.50 that is now 46 days overdue. XBert identifies that invoices of this size are usually paid within 28–45 days. Because this invoice has exceeded the typical overdue threshold, it is flagged for your attention. The alert suggests you prioritise follow-up, as this delay is outside your customer’s usual behaviour and poses an increased collection risk.

Accounting software

All major Australian-compatible accounting software (e.g., Xero, MYOB, QuickBooks Online).

Which countries it supports

All regions.

Processes

This alert falls under the ‘Sales (AR)’ category and supports proactive credit control and cash flow protection. To resolve this issue:

  • Confirm bank reconciliation is up to date to ensure payment hasn’t been received and not matched.

  • Contact the customer to request immediate payment or agree on a payment plan.

  • Review the customer’s credit terms — consider shortening payment terms or requesting upfront payments in the future.

  • Make payment easier — ensure you're offering convenient payment options.

  • Automate reminders — if using Xero, enable invoice reminders to automatically notify clients when payments are due or overdue. Learn more on Xero Central.

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