Invoice Letter Template
Updated July 7, 2026 | Business
Professional invoice template for billing clients and customers.
Quick Answer
Use this invoice letter template to create a clear, signed, mail-ready record. Fill in the bracketed details, review any legal or policy requirements, then copy, download, or send it online with tracking.
When to Use This Invoice Letter Template
- Professional invoice template for billing clients and customers.
- The recipient requires a signed letter or written notice.
- You need a dated paper trail before a deadline or dispute escalates.
- You want delivery tracking and a copy for your records.
- You need a reusable starting point that can be customized before mailing.
Invoice Letter Template
The Letter Pilot
Mail-ready template
Payment record
INVOICE
[Your Company/Business Name]
[Your Address]
[City, State, ZIP Code]
[Phone Number]
[Email Address]
[Website]
INVOICE NUMBER: [INV-XXXX]
INVOICE DATE: [DATE]
DUE DATE: [DATE]
BILL TO:
[Customer/Client Name]
[Company Name, if applicable]
[Address]
[City, State, ZIP Code]
[Email]
[Phone]
SHIP TO (if different):
[Name]
[Address]
[City, State, ZIP Code]
---
INVOICE DETAILS:
| Item/Description | Quantity | Unit Price | Amount |
|--------------------------------|----------|------------|-----------|
| [Product/Service 1] | [QTY] | $[PRICE] | $[TOTAL] |
| [Product/Service 2] | [QTY] | $[PRICE] | $[TOTAL] |
| [Product/Service 3] | [QTY] | $[PRICE] | $[TOTAL] |
| [Additional items as needed] | | | |
---
SUBTOTAL: $[AMOUNT]
DISCOUNT: -$[AMOUNT]
TAX ([X]%): $[AMOUNT]
SHIPPING: $[AMOUNT]
─────────────────────────
TOTAL DUE: $[AMOUNT]
═════════════════════════
---
PAYMENT INFORMATION:
Payment Terms: [Net 30 / Due on Receipt / Other]
Due Date: [DATE]
Accepted Payment Methods:
☐ Check payable to: [Your Business Name]
☐ Credit Card (contact us to pay by card)
☐ Bank Transfer:
Bank Name: [BANK NAME]
Account Name: [ACCOUNT NAME]
Account Number: [ACCOUNT NUMBER]
Routing Number: [ROUTING NUMBER]
☐ Online Payment: [PAYMENT LINK/PORTAL]
☐ PayPal/Venmo: [ACCOUNT]
☐ Other: [Specify]
---
REFERENCE INFORMATION:
Purchase Order Number: [PO #, if applicable]
Project Name: [PROJECT, if applicable]
Service Period: [DATE RANGE, if applicable]
---
NOTES/TERMS:
[Include any relevant notes, such as:]
- Thank you for your business!
- Late payments may be subject to a [X]% monthly finance charge.
- Please include invoice number with your payment.
- Questions? Contact us at [EMAIL] or [PHONE].
---
LATE PAYMENT TERMS:
Payments received after the due date may be subject to:
☐ Late fee of $[AMOUNT] or [X]% of the balance
☐ Interest charge of [X]% per month on overdue balances
☐ Suspension of services until payment is received
☐ Collection proceedings and associated costs
---
[Your Company Name] appreciates your business!
For questions regarding this invoice, please contact:
[Contact Name]
[Email]
[Phone]
---
PAYMENT REMINDERS:
☐ Payment due within [NUMBER] days
☐ Early payment discount: [X]% if paid within [NUMBER] days
☐ Preferred payment method: [METHOD]
---
INVOICE COPY PURPOSES:
☐ Customer Copy
☐ Accounting Copy
☐ File Copy
---
SENDER'S RECORD:
Invoice Number: ________________
Date Sent: ________________
Amount Due: $________________
Payment Received Date: ________________
Payment Amount: $________________
Balance Remaining: $________________
Need to mail this with tracking? The Letter Pilot handles postage, tracking, and Certified Mail options online.
How to Use This Invoice Letter Template
- Customize the placeholders. Replace every bracketed field with the sender, recipient, date, account, address, amount, or case details that apply.
- Review requirements. Check the contract, agency instructions, court rule, state law, or recipient policy before sending.
- Attach supporting copies. Include copies of relevant notices, receipts, records, photos, invoices, or forms when they strengthen the letter.
- Keep your records. Save a copy of the completed letter and any attachments before mailing.
- Send with tracking when it matters. Use Certified Mail or another tracked service when timing, proof of delivery, or dispute documentation matters.
Mailing and Recordkeeping Tips
- - Keep the tone direct, factual, and professional.
- - Use copies of supporting documents unless originals are specifically required.
- - Save the completed letter, attachments, mailing receipt, and tracking number together.
Invoice Letter Template FAQ
What should be included in a professional invoice?
A professional invoice should include: your business info, client info, unique invoice number, date issued, due date, itemized list of products/services with prices, subtotal, taxes, total due, and payment instructions.
What payment terms should I set?
Common terms include Net 30 (due in 30 days), Net 15, Net 60, or Due on Receipt. Choose based on your industry standard and cash flow needs. You can also offer early payment discounts like 2/10 Net 30 (2% discount if paid within 10 days).
Can I charge late fees on overdue invoices?
Yes, but your right to charge late fees should be stated upfront (on the invoice or in your contract). Typical late fees range from 1-2% per month. Some states have laws limiting late fees, so check your jurisdiction.
Should I send invoices by mail or email?
Email is faster and more common for regular invoices. Use certified mail for past-due invoices or disputes to create a legal record of delivery. Services like The Letter Pilot make it easy to send invoices via certified mail when you need proof of delivery.
How do I follow up on unpaid invoices?
Send a friendly reminder a few days before due date, then follow up immediately after it becomes past due. Escalate with formal collection letters if needed. Keep records of all communication.
What is the difference between an invoice and a bill?
They are essentially the same document. "Invoice" is typically used by the business sending the request for payment. "Bill" is typically used by the customer receiving it.
Is an invoice a legal document?
An invoice itself is not a contract, but it serves as important documentation of a transaction and payment terms. It can be used as evidence in court to support a claim for payment. For best protection, have a signed contract or agreement in addition to your invoices.
Do I need to sign an invoice for it to be valid?
No, invoices do not require a signature to be valid. However, having the customer sign a delivery receipt or work completion form provides additional proof that goods or services were received.
Legal Advice Disclaimer: This template is provided for general informational purposes only and does not constitute legal advice. Consult a qualified professional for advice specific to your situation.
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Ready to mail the final letter?
Customize this template, then continue to online mailing with tracking.