Receiving timely payments for services rendered is an absolute necessity from a business perspective, particularly for SMEs and new ventures that work digitally and remotely. All of these entities must preserve their brand image and client relations, and that begins with crafting well-written invoice emails to request payment.
An invoice email is an electronic message sent to a client or customer requesting payment for goods or services they have ordered. Good invoice emails can improve sales and put the business on steady financial ground. Accurate and proficient invoicing can become the basis for smooth business operations, all while reducing unpaid invoices. Setting out well-defined procedures for invoicing is of utmost importance for all businesses dealing with foreign suppliers and clients, such as companies based in Hong Kong.
This guide aims to explain how to write an invoice email with instructions and examples. We’ll also discuss which email communication aspects must be followed when you request payment for your business.
Key Elements of a Professional Invoice Email
Knowing how to write an invoice professionally is a critical part of running a smooth and professional business. In Hong Kong’s competitive and fast-paced business environment, where time and clarity are highly valued, ensuring your invoice communication is on point can directly impact how quickly you get paid.
Below are six essential invoice details to include in a standard invoice email format:
1. A Clear and Informative Subject Line
When you write an invoice email, the subject line should be specific and include all the relevant details to immediately capture attention. Here's a good example of an invoice email subject line:
“Invoice #INV-2043 – Payment Due 25 June 2025”
This removes ambiguity and ensures your message doesn’t get lost in a crowded inbox. Clear subject lines that include the invoice number are especially useful.
2. Personalised Greeting
Always address your recipient by name, such as “Hi John,” or “Dear Ms. Wong,” depending on your level of formality. A personalised invoice email greeting shows professionalism and builds rapport, which is particularly important in Hong Kong’s business culture, where relationship management is key.
3. Short and Clear Message Body
The core invoice email message should be concise yet informative. Include the invoice number, the total amount due in HKD, the payment due date, and a brief description of what the invoice covers. Avoid lengthy explanations—clarity helps to avoid confusion and prevents payment delays.
Invoice email example:
“Please find attached Invoice #INV-2043 for consulting services delivered between June 1–15, 2025. The total due is HKD 12,000, payable by 25 June 2025.”
4. Invoice Attached (PDF Format)
Always attach the invoice payment document to your invoice email in a standard, non-editable format like PDF. This makes it easy for the client to save, print, and forward to their accounts team. Make sure the invoice is clearly labelled and includes your business details, logo, payment terms, and a clearly attached invoice document.
5. Payment Details
Clearly outline how the client can pay you in the invoice email template. Include accepted payment methods, such as bank transfer, online payments, credit cards, or a specific platform. Mention any relevant account numbers and the payment deadline to help avoid overdue invoices. You may also include payment links. If necessary, include details about late payment fees in case your client’s payment exceeds the due date.
Providing multiple payment options, accurate bank account details, and clear payment instructions increases the likelihood of timely settlement, speeds up the payment process, and leads to fewer overdue invoices.
6. Contact Information
After including all the necessary details, don't forget to also include your direct contact details so the client can reach out with questions or clarifications. This could be your email, phone number, or both. Making it easy to contact you helps resolve to potential issues quickly and builds trust.
How to Create a Clear and Concise Invoice Email
When it comes to unpaid and upcoming invoices, a well-written invoice email is everything. A clear and concise invoice email not only improves your chances of getting paid faster but also reflects professionalism and respect for your client’s time. In Hong Kong’s fast-moving, efficiency-driven business landscape, where many SMEs work with regional or international partners, streamlined communication is especially crucial.
Confusing invoice email templates, missing payment methods and details, or vague subject lines that lack payment instructions can lead to unnecessary delays. Worse, your email might get ignored or lost in a cluttered inbox.
Fortunately, nowadays, you can create an invoice email using free invoice templates or invoicing software available online. However, you can also use this template below to help you write an invoice email.
Subject Line:
“Invoice #2043 for Marketing Services – Due 25 June 2025”
Greeting:
“Dear Ms. Lee,”
Email Body:
“I hope this message finds you well.
Please find attached Invoice #2043 for the digital marketing services delivered on 1–15 June 2025. The total amount payable is HKD 12,000, due by 25 June 2025.
Kindly arrange payment via your preferred method. If you have any questions about the invoice, need clarification, or if payment has already been made, you can contact us at [insert contact details]. We look forward to receiving payment from you.
Thank you for your prompt attention.”
Closing:
Best regards,
[Your Name]
[Your Position]
[Your Company Name]
By keeping your emails concise and polite, you’ll increase the chances of timely payments without sounding overly formal.
What is a Past-Due Invoice Email?
Even with clear payment terms and a smooth invoicing process, delays and unpaid invoices still happen, especially when working with multiple clients or across time zones. That’s where past-due invoice emails become essential.
These invoices are follow-up messages to encourage prompt payment of unpaid invoices sent to remind clients that payment has not been received by the due date. They can also help you identify underlying issues that may be causing clients to delay payment.
The goal of a past-due email is to prompt payment without damaging the client relationship. It’s important to strike the right tone: professional, polite, but firm. Avoid sounding accusatory—instead, approach it gently.
A well-crafted past-due invoice email should include:
Subject Line:
“Reminder: Invoice #2043 Overdue – Payment Needed”
Email Body:
“Dear Ms. Lee,
I hope you’re doing well.
This is a friendly reminder that Invoice #2043, issued on 15 June 2025, remains unpaid. The total amount of HKD 12,000 was due on 25 June 2025.
Please arrange payment at your earliest convenience to avoid any late penalties. If payment has already been made, kindly disregard this message.
Feel free to reach out with any questions.
Best regards,
[Your Name]
[Your Company Name]”
Tip: Send your first reminder 3–5 business days after the due date.
Tips to Improve Communication with Clients and Avoid Late Payments
If late payments are affecting your cash flow, improving how you communicate can make a big difference. Here are five practical strategies relevant to Hong Kong-based businesses working with local and international clients:
1. Set Clear Expectations Upfront
Always define your payment terms in your client agreements and in the invoice email, including due dates, accepted payment methods, and late fees (if applicable).
For Hong Kong businesses dealing with overseas clients, it's especially important to specify currency and payment timelines clearly. If you're invoicing in foreign currencies, using Aspire’s Global Payments can help you send and receive funds seamlessly in HKD or other supported currencies.
2. Send Invoices Promptly
Avoid delays on your end. As soon as a service is delivered or a project milestone is completed, issue the payment request. In Hong Kong’s fast-moving business culture, waiting too long can lead to lost priority or administrative backlog on the client’s side.
3. Automate Follow-Ups
Manual follow-ups take time and can easily fall through the cracks. Use a financial platform like Aspire to automate reminder emails at key intervals—before the invoice email due date, on the due date, and after if needed. This keeps your payment cycle moving and avoids awkward conversations, which is particularly useful when dealing with culturally sensitive client relationships in Hong Kong and other parts of Asia.
4. Maintain Open, Friendly Dialogue
If a client misses a payment, reach out with a polite and understanding tone. Ask if there are any issues on their end and offer flexibility if appropriate. In Hong Kong, maintaining strong guanxi (relationships) is essential for long-term business, so a collaborative approach can go a long way in preserving trust while resolving payment issues.
5. Offer Convenient Payment Options
Clients are more likely to pay invoice emails on time when they have options. Whether they prefer bank transfers, card payments, or cross-border solutions, offering flexibility can speed things up.
Simplify Your Invoice Management with Aspire
Invoicing and invoice emails don’t need to be complicated. An Aspire Business Account makes it easier for businesses in Hong Kong to manage invoices efficiently.
The Aspire Business Account comes with an invoice management feature, allowing you to create and send invoices in just a few clicks. Say goodbye to late payments—Aspire allows you to set up automatic payment reminders, ensuring that customers pay on time. You can also view all paid and unpaid invoices at a glance and seamlessly integrate this data with your preferred accounting software.
Need better control over team spending? Aspire’s Corporate Cards lets you assign individual cards to employees and monitor transactions in real time. When it comes to staying on top of operational costs, the expense management feature helps you organise and categorise expenses without the hassle of manual reconciliation.
Aspire helps you simplify your entire invoice workflow and maintain a healthier cash flow. Sign up today and experience a smarter way to handle your finances.
Frequently Asked Questions
What is the importance of payment confirmation?
Payment confirmation after invoice emails act as formal proof that a transaction has been completed. It gives both you and your client peace of mind and helps maintain accurate financial records. It’s also useful for audits and compliance checks.
What are the differences between bills and invoices?
An invoice email is a detailed request for payment, typically issued after goods or services are delivered. It includes the due date, total amount, and payment terms. A bill, on the other hand, is often paid immediately.
How can I ensure my invoice emails are not overlooked?
In your invoice email, start with a clear subject line, use the client’s name, and keep your message brief but informative. Attach the invoice as a PDF and include straightforward payment instructions. If you don’t get a response, follow up politely within a few days.
What should I do if a client consistently pays late?
Start by checking in with the client to understand the cause of the delays. If the issue continues, consider requesting upfront deposits, adding late fees, or shortening payment terms in your invoice email.
Can I automate my invoicing process?
Yes, automation can save time and reduce errors. With Aspire, you can auto-generate invoices, set up payment reminders, and track what’s been paid—all from one platform.
Frequently Asked Questions
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