How to Send an Invoice by Email: 7 Copy-and-Paste Templates

Use templates 1–4 when requesting payment for the first time, template 5 before an existing invoice is due, template 6 after its due date, and template 7 when you need to correct an invoice. Copy the subject and message for your situation, then check them against the attached document.

The email summarizes the request; the invoice contains the detailed charges and billing information. Confirm your client’s preferred billing contact, purchase order requirements, and whether they need the invoice uploaded to a portal as well.

Use this when sending your first bill to a client. Ask them to confirm that it reached the right billing contact, especially if your project contact does not process payments.

Subject: Invoice [invoice number] for [project] — due [due date]

Hi [client name],

Thank you for working with [your business name]. I’ve attached invoice [invoice number] for [brief description of work]. The amount due is [amount and currency], payable by [due date], as agreed.

Payment instructions are included on the invoice. Please use [invoice number] as your payment reference.

Could you confirm receipt and let me know if your accounts team needs a purchase order number or any additional billing information?

Best regards, [your name] | [business name] | [contact email]

Use this when the agreed work or billable milestone is complete. If a deposit has already been paid, the amount requested should be the remaining balance shown on the invoice.

Subject: Invoice [invoice number] — [completed project or milestone]

Hi [client name],

The [project or milestone] is complete, and I’ve attached invoice [invoice number] for the agreed work. The remaining amount due is [amount and currency], with payment due on [due date].

The invoice lists the deliverables and any payments already credited. Please follow the payment instructions on the document and use [invoice number] as the reference.

Thank you for the opportunity to work on this project. Please let me know if you have any questions about the invoice.

Best regards, [your name] | [business name] | [contact email]

Use this for a retainer or recurring service. Name the actual service period so the client can distinguish this invoice from previous months.

Subject: [Month and year] [service] invoice — [invoice number]

Hi [client name],

Attached is invoice [invoice number] for [service] provided from [period start] to [period end]. The total due is [amount and currency], payable by [due date].

The invoice includes [brief summary of the agreed services or hours]. Payment instructions are on the attached document; please quote [invoice number] when paying.

Please let me know if you need any supporting details for this billing period. Thank you for your continued business.

Best regards, [your name] | [business name] | [contact email]

Use this only when you and the client have agreed to a deposit. State the amount requested now separately from the full project price. Adapt the start date and remaining payment schedule to your agreement.

Subject: Deposit invoice [invoice number] — [project name]

Hi [client name],

As agreed, I’ve attached invoice [invoice number] requesting a deposit of [deposit amount and currency] for [project name]. This is [percentage]% of the agreed project total of [project total and currency].

The deposit is due by [due date]. The remaining [balance and currency] will be billed at [agreed milestone or date]. Our agreed start arrangement is [start date or condition].

Please use the payment instructions on the invoice and quote [invoice number]. Let me know if you need any information before arranging payment.

Best regards, [your name] | [business name] | [contact email]

Use this for an unpaid invoice approaching its due date. Check your payment records first. A reminder sent a few business days before the deadline is one possible schedule; adapt it to the client’s payment process.

Subject: Reminder: invoice [invoice number] due [due date]

Hi [client name],

A quick reminder that invoice [invoice number] for [project or service], totaling [amount and currency], is due on [due date]. I’ve attached a copy for convenience.

Payment instructions are included on the invoice. If you’ve already arranged payment, thank you—please let me know so I can update my records.

If anything is missing for your accounts team to process it, I’m happy to help.

Best regards, [your name] | [business name] | [contact email]

Use this once the due date has passed and your records still show an unpaid balance. Ask for a payment update without assuming the client deliberately withheld payment. If they dispute a charge, resolve that issue before repeating the same reminder.

Subject: Payment update requested — invoice [invoice number]

Hi [client name],

I’m following up on invoice [invoice number] for [project or service], which was due on [original due date]. My records show an outstanding balance of [amount and currency]. I’ve attached the invoice again for reference.

Could you confirm whether payment has been scheduled and the expected payment date? If payment has already been sent, please share the payment date and reference so I can reconcile it.

Please let me know if there is a billing question or missing information holding this up.

Best regards, [your name] | [business name] | [contact email]

Use this when a sent invoice needs correction. Identify the changed field and explain which document the client should use. The appropriate correction document and numbering depend on your accounting process and local requirements; preserve the original record.

Subject: Correction to invoice [original invoice number] — [project]

Hi [client name],

I noticed an error in [field or line item] on invoice [original invoice number]. I’m sorry for the confusion. Attached is [corrected invoice or adjustment document reference], which [brief explanation of the correction].

The correct amount now due is [amount and currency], payable by [confirmed due date]. Please use [document reference] when processing payment and disregard the superseded payment request where applicable.

If you have already paid the original amount, please let me know before making another payment so we can reconcile the difference.

Thank you for your understanding.

Best regards, [your name] | [business name] | [contact email]

Here is a fictional example you can recreate in SwiftInvoice. Alex Morgan Design has completed a website audit and landing page design for Example Studio. For this illustration, no tax applies, and there are no deposits, discounts, or extra charges. These assumptions are not tax guidance for your own business.

Enter your supplier and client details, invoice reference, dates, currency, and the two line items in the invoice generator. Add the agreed payment instructions, review the preview, and save the invoice as a PDF. Open the saved file before attaching it to an email from your usual email account.

• Supplier: Alex Morgan Design, [supplier billing address], alex@example.com
• Client: Example Studio, [client billing address], billing@example.com
• Invoice: AMD-2026-001; issued October 27, 2026
• Website audit: 3 hours × $50 USD = $150 USD
• Landing page design: 1 × $300 USD = $300 USD
• Subtotal and total due: $450 USD under this example’s no-tax assumption
• Due date: November 10, 2026, under agreed 14-day terms
• Payment instructions: [verified bank transfer details]; reference AMD-2026-001
• Suggested attachment filename: AMD-2026-001-Example-Studio.pdf

Subject: Invoice AMD-2026-001 — website audit and landing page design

Hi [client name],

I’ve attached invoice AMD-2026-001 for the completed website audit and landing page design. The total due is $450 USD, payable by November 10, 2026, under our agreed 14-day terms.

Please pay using the bank transfer instructions on the invoice and use AMD-2026-001 as the reference. Let me know if your accounts team needs any additional information.

Thank you for working with me.

Best regards, Alex Morgan | Alex Morgan Design | alex@example.com

The email amount, due date, and reference match the invoice exactly. Use your own details and agreed terms rather than copying the fictional dates into a live invoice.

Replace all placeholders and remove instructions that do not apply. An email with a missing attachment or a conflicting amount creates extra work for the person processing it.

• Send to the confirmed billing address; copy the project contact only when appropriate.
• Check the invoice reference, amount, currency, due date, and payment instructions against the PDF.
• Use a specific subject line and a recognizable attachment filename.
• Open the attachment to confirm it is the final invoice for the correct client.
• If you include a payment link, use your verified payment provider’s link and check its destination.
• Confirm any changed bank details with the client using an established contact channel.
• Keep the sent email and final invoice together so you can track follow-ups and payments.

A PDF attachment is a practical option because it keeps the invoice as a separate document that the client can save or forward. Include a short summary in the email as well. If the client requires a supplier portal or another format, follow that process.

SwiftInvoice helps you prepare the invoice document. Send the saved PDF through your own email account; these templates do not automatically send emails or collect payments.

Use the invoice number and project or service name, adding the due date when helpful. For example: “Invoice AMD-2026-001 — website audit — due November 10.” This gives the client enough context to identify the bill without opening every attachment.

Avoid an unexplained “Payment needed” subject or an urgent label on an invoice that is not overdue. For a correction, say that it is a correction so the client does not treat it as a second charge.

Follow the payment schedule you agreed, and check whether the transfer is already in progress before sending a reminder. If an invoice is overdue, start with a polite request for a payment update. Keep later follow-ups in the same email thread when that helps preserve context.

Do not introduce new fees or new payment terms through a reminder template. If there is a disagreement, discuss the specific charge or missing document with the client and record the resolution.