How to Send an Invoice to a Client (Email + PDF Guide)

Creating a great invoice is only half the job. How and when you send it matters just as much. This guide covers the professional way to send an invoice to a client and follow up without damaging the relationship.

When to Send an Invoice

The golden rule: send your invoice as soon as the work is complete. Every day you delay is a day payment is further away.

• Project-based work: Send immediately upon delivery
• Hourly/ongoing work: Send at the end of each week or month
• Retainer clients: Send on the 1st of each month

How to Send the Invoice

PDF via email is the professional standard. Here is the exact process:

1. Create your invoice — use ai-invoicemaker.com to generate a professional PDF
2. Download the PDF — name your file descriptively: Invoice_INV-001_YourName.pdf
3. Open your email client — Gmail, Outlook, or other
4. Attach the PDF
5. Write your email — see the templates below

Invoice Email Subject Lines

• Invoice #INV-001 from [Your Name] – Due [Date]
• [Project Name] Invoice – [Your Business Name]

Invoice Email Template

Tips to Get Paid Faster

• Set a clear due date — use Net 15 or Net 30
• Make it easy to pay — include bank details on the invoice
• Follow up on time — 3 days before due date and if overdue