You have completed the work, prepared the invoice, and now it is time to send it to the client. But what should the email say? A poorly worded invoice email can lead to delayed payments, confusion, or even a strained client relationship. On the other hand, a professional, clear invoice email increases the likelihood of prompt payment and reinforces your credibility.
Many professionals underestimate the importance of the email that accompanies an invoice. They simply attach the PDF and write "Invoice attached" in the body. While this gets the job done, it misses an opportunity to set clear expectations, maintain a professional tone, and make the payment process as smooth as possible for the client. This guide takes a step-by-step approach to sending invoice emails, covering the wording, structure, and common mistakes to avoid. You will also get three ready-to-copy templates for different scenarios.
Why a Professional Invoice Email Matters
The email you send with your invoice is often the final touchpoint in a project. It shapes the client's perception of your professionalism and can influence how quickly they prioritise your payment. A clear, courteous invoice email demonstrates that you are organised, respectful of the client's time, and serious about your business.
Beyond perception, a well-written invoice email also reduces the back-and-forth. When you include all necessary details—invoice number, amount, due date, payment methods, and a clear subject line—the client has everything they need to take action immediately. This minimises follow-up questions and accelerates the payment cycle.
Finally, a consistent invoicing process helps you maintain accurate financial records. When every invoice email contains the same essential information and follows a standard format, it becomes easier to track outstanding payments, resolve disputes, and manage your cash flow.
Common Wording Mistakes to Avoid
Even a small phrasing error can lead to confusion or delay. Here are the most common wording mistakes professionals make when sending invoices by email—and how to fix them.
- Being too vague: An email that simply says "Invoice attached" does not tell the client what the invoice is for, how much it is, or when it is due. Always include a brief summary of the work, the amount, and the due date.
- Using an aggressive tone: Language like "Payment is required immediately" or "This invoice is overdue" can put clients on the defensive. Even if the invoice is overdue, a polite and firm tone works better.
- Failing to specify the due date: Do not assume the client will look at the invoice attachment to find the due date. State it clearly in the email body.
- Not explaining the payment method: If you have specific payment instructions (e.g., bank transfer, PayPal, online portal), include them clearly in the email. Remove any barriers to payment.
- Using an unclear subject line: A subject like "Invoice" is generic and may be overlooked. Always include the invoice number and your company name.
- Forgetting to thank the client: A simple thank-you for their business goes a long way in maintaining a positive relationship.
Pro Tip: Always Attach the Invoice in PDF Format
PDF is the universal standard for invoices. It preserves formatting and cannot be easily altered. Avoid sending invoices in editable formats like Word or Excel, as they can be changed unintentionally.
Three Ready-to-Use Invoice Email Templates
Below are three distinct templates for sending invoices. Choose the one that best fits your relationship with the client and the context of the work.
Template 1: Standard Professional Invoice (Best for Most Clients)
Subject Line Options: "Invoice [Invoice Number] from [Your Company]" / "[Client Name] – Invoice [Number]" / "Invoice for [Project Name] – [Date]"
Subject: Invoice [Invoice Number] from [Your Company]
Dear [Client's Name],
I hope you are having a good week. Please find attached Invoice [Invoice Number] for the work completed on [Project Name / Services Provided].
A summary of the invoice is as follows:
- Invoice Number: [Invoice Number]
- Total Amount: [Amount]
- Due Date: [Due Date]
Payment can be made via [payment method, e.g., bank transfer / PayPal / online portal]. Our bank details and payment instructions are included in the invoice attachment.
Please do not hesitate to contact me if you have any questions or need any additional information. We greatly appreciate your business and look forward to working with you again in the future.
Thank you for your prompt attention to this matter.
Best regards,
[Your Full Name]
[Your Job Title]
[Your Company Name]
[Your Phone Number]
Template 2: Short and Direct Invoice (Best for Regular Clients or Retainers)
Subject Line Options: "Invoice [Number] for [Service Period]" / "[Client] – Invoice [Number] Attached" / "Payment Request – Invoice [Number]"
Subject: Invoice [Number] for [Service Period]
Dear [Client's Name],
Please find attached Invoice [Number] for [Service/Retainer] for [period, e.g., "July 2026"]. The total is [Amount] and is due by [Due Date].
You can pay via [payment method]. Details are in the attachment.
If you have any questions, please let me know. Thank you for your continued trust in our services.
Sincerely,
[Your Full Name]
[Your Job Title]
[Your Company Name]
[Your Phone Number]
Template 3: Detailed Invoice Email with Breakdown (Best for Complex Projects)
Subject Line Options: "Invoice [Number] – Detailed Breakdown for [Project]" / "[Project Name] Final Invoice" / "Invoice and Project Summary – [Client Name]"
Subject: Invoice [Number] – Detailed Breakdown for [Project]
Dear [Client's Name],
I am pleased to present the final invoice for the [Project Name] project. As discussed, the total cost is [Amount], with payment due by [Due Date].
A detailed breakdown of the work performed is included in the attached invoice. For your reference, the key items are:
- [Service/Item 1]: [Amount]
- [Service/Item 2]: [Amount]
- [Service/Item 3]: [Amount]
- Total: [Amount]
Please let me know if you have any questions about the breakdown or the invoicing process. Payment instructions are included in the attachment.
I value our collaboration and look forward to future opportunities. Thank you for your trust and prompt attention.
Warm regards,
[Your Full Name]
[Your Job Title]
[Your Company Name]
[Your Phone Number]
Checklist: What to Include in Every Invoice Email
Before you hit send, review your invoice email against this checklist. These elements ensure your email is complete, professional, and ready for payment.
- Clear subject line: Include your company name, invoice number, and the word "Invoice".
- Personalised greeting: Address the client by name.
- Invoice summary: State the invoice number, total amount, and due date clearly in the email body.
- Brief description of work: Mention what the invoice is for (project name or service period).
- Payment instructions: Clearly explain how the client can pay (bank transfer details, link to payment portal, etc.).
- Attached invoice: Always attach the invoice as a PDF. Mention the attachment in the email.
- Thank you: Express gratitude for their business.
- Professional closing: Include your full name, job title, company name, and phone number.
- Proofread: Check for typos, incorrect amounts, or wrong dates.
Warning: Never Send an Invoice Without a Due Date
An invoice without a due date gives the client no incentive to pay promptly. Always include a clear due date in both the attachment and the email body. If you have a standard payment term (e.g., "Net 15"), state it explicitly.
What to Do If a Client Doesn't Respond or Pay
You sent the invoice email, and days have passed without a response. This is not uncommon, but it requires a professional follow-up strategy. The key is to remain polite and systematic, not aggressive or anxious.
If you have not received payment or an acknowledgment within 3-5 business days after the due date, send a gentle follow-up. A simple email asking if they received the invoice and if there are any issues often resolves the situation. Offer to resend the invoice if needed.
If the client still does not respond after the first follow-up, send a second reminder about a week later, adopting a slightly firmer tone while still maintaining professionalism. State the overdue amount and the number of days overdue. Suggest they contact you if there are any concerns.
For chronic late payers, consider implementing a clear payment policy that includes late fees, suspension of services, or a requirement for deposits. These policies should be communicated clearly in your initial terms of engagement. At the end of the day, timely payment is a matter of mutual respect, and you are entitled to enforce your terms when necessary.
Frequently Asked Questions
Q. What should I write in the subject line of an invoice email?
A. Use a clear, professional subject line that includes your company name, the word "Invoice," and the invoice number. For example: "Invoice #1024 from [Your Company]." This ensures the client immediately knows the purpose of your email.
Q. Is it okay to send an invoice as an attachment?
A. Yes, it is the standard practice. Always use PDF format to prevent editing. In the email, clearly mention that the invoice is attached and provide a summary of the amount and due date in the body for quick reference.
Q. How do I send an invoice via email if the client uses a different currency?
A. Clearly state the currency in both the email body and the invoice attachment. If you are using a currency converter, mention the exchange rate used. It is also helpful to confirm payment currency with the client beforehand.
Q. Should I include payment terms in the invoice email or just the attachment?
A. Include payment terms in both places. State the due date and any late fees clearly in the email body, and repeat them in the invoice document. This reduces the chance of the client missing important information.
Q. What if the client asks me to resend the invoice?
A. Resend the invoice promptly with a polite note such as: "Here is the invoice as requested. Please let me know if you need any further information." Keep a record of the resend date and any communication.
Q. How do I follow up on an unpaid invoice without sounding aggressive?
A. Use a polite, friendly tone. Assume the client may have simply forgotten or been busy. Offer assistance if they have questions. For example: "I just wanted to check if you received the invoice sent on [Date]. If you have any questions, please let me know. If you've already processed payment, thank you!"