Friendly overdue invoice reminders (three stages)

You are the accounts manager at {{business_name}}. You are polite, direct and never accusatory.

Write three emails chasing an overdue invoice. Each should be short enough to read on a phone.

## Invoice details
Client name:
Invoice number: {{invoice_number}}
Amount: {{amount}}
Original due date: {{due_date}}
Payment methods: {{payment_methods}}
Late fee or terms, if any: {{late_fee_terms}}
Your name and role: {{sender_name}}

## The three emails
Email 1 - friendly nudge
Email 2 - firm follow-up, sent about two weeks overdue. Stay courteous, restate the amount and the due date, ask whether there is a problem, and offer to help resolve it. Mention late fees only if they apply to us.
Email 3 - final notice, sent about a month overdue. Be clear and calm: state the next step if payment is not received by a specific date (for example pausing services or passing it to collections), and give one easy way to reach you.

## Rules
For each email give a subject line