How to Send an Invoice: Email, Link or PDF (+ 6 Invoice Email Templates)

Sending an invoice sounds like the easy part: attach a file, press send. Yet this is where invoices go missing, land in a spam folder, or reach someone who cannot pay them. The short answer is below, and the rest of this guide covers each channel honestly, six email templates you can paste, and what to do once the invoice has left your outbox.

How to send an invoice in 5 steps

• Check the invoice. Number, issue date, due date, amounts, currency and payment details must all be right before it leaves.
• Pick the channel. Email with a PDF attached, a share link, an invoicing tool, or PayPal or Square if your client pays that way.
• Send it to the person who pays, not only the person who hired you. Use a subject line that holds the invoice number, your name and the due date.
• Confirm receipt. Ask for a one-line acknowledgement, and write the due date in your own calendar.
• Schedule one reminder for a few days before the due date, so the follow-up is already decided.

If the invoice itself is not written yet, start with how to write an invoice and come back. This post is only about getting it delivered. If it is already overdue, skip to how to ask for payment professionally.

Before you send: a checklist

Ten seconds of checking saves a week of back and forth. A corrected invoice usually needs a new number or a credit note, and accounting teams do not enjoy either.

• Invoice number: unique and in sequence, with no gaps you cannot explain.
• Issue date and due date: both written out as dates, not only as "Net 30". The invoice payment terms guide explains the options.
• Payment terms and any late fee, stated the same way as in your contract.
• Payment details: bank name, account holder and account number, or a payment link. For a client in another country add the IBAN and SWIFT/BIC.
• Currency: stated once, clearly, next to the total.
• Recipient: the accounts payable address or billing contact if you have one, plus the client's PO number if they use them.
• Tax IDs where the rules require them, yours and the client's. If you are unsure, ask your accountant before the first invoice, not after.

Ways to send an invoice, with the honest trade-offs

Email with a PDF attached

Still the default, and still fine for most freelance work. Name the file something a stranger can sort later, such as Invoice-2026-014-YourName.pdf. Put the amount, due date and payment method in the body as well, because many people read the email and never open the attachment. If you need to know how to send an invoice via email for the first time, templates one and two below are the whole recipe.

A share link

A link means the client opens a page instead of a file. It is useful when you want to correct an error without a second email chain, or when you want to see whether anyone looked at it. The weakness is the inbox: a link in a short email from an unknown sender is exactly what spam filters distrust. Send the link in a normal sentence, and offer the PDF if the client prefers it.

An invoicing tool

Sending from the tool that created the invoice keeps the number, the PDF and the sent date in one place. In QuickBilling you can email an invoice with to, cc and bcc fields, your own subject and message, or generate a share link instead. Bank details or a payment-link URL show on the PDF and on the share page. QuickBilling does not process card payments itself, so the payment details you add are the way your client pays you.

PayPal invoices

To send an invoice on PayPal, create an invoice in PayPal's invoicing section, add the client's email address and the line items, review it, and choose Send. According to PayPal's help centre, you can send an invoice to any email address in the world, and you can also share a link to it by email, text or messaging app. The client does not need to be a PayPal customer to receive it. Fees apply when the client pays through PayPal, so read the current fee page for your country before you quote a price. PayPal changes its menus often, so follow its own help article rather than a screenshot from an older guide.

Square invoices

To send an invoice on Square, create it in the Square Dashboard or app, choose the customer, add the items and a due date, and send it. Square's help centre lists email, text message (only if the customer asked for it and a mobile number is on file) and a shareable payment link as delivery options. It suits a business that already takes card payments through Square. If you are a freelancer without a Square account, a plain PDF over email is less work.

E-invoices in Germany: what changes and when

A structured e-invoice is a machine-readable file (XML), not a picture of an invoice. A PDF attached to an email is not an e-invoice, and neither is a share link. For German B2B invoices the rules are phased in. Receiving structured e-invoices has been mandatory since 1 January 2025. For issuing, the Federal Ministry of Finance's guidance of 15 October 2025 keeps transition rules until 31 December 2027: through 2026 you may still send a PDF by email, as long as the client agrees (silent acceptance counts). In 2027 that relief only applies if your turnover in the previous year was up to €800,000. From 1 January 2028, B2B invoices between German businesses must be structured e-invoices such as XRechnung or ZUGFeRD.

Two exemptions matter to freelancers: invoices up to €250 and invoices from small businesses under the Kleinunternehmerregelung can always be issued as ordinary invoices. Other countries have their own timelines, and this is not tax advice, so confirm your case with an accountant. For the details, read whether a PDF counts as an e-invoice and the XRechnung versus ZUGFeRD comparison for German freelancers.

Subject lines that get opened

A subject line has one job: let the right person recognise the email as a bill and file it. Clever does not help. These work because they carry the three things accounts payable searches for.

• Invoice [Invoice #] from [Your name], due [date]. The number and the due date are what someone types into a search box later.
• Invoice [Invoice #] for [project name]. Use this when the client's AP team matches invoices to project names or PO numbers.
• [Your business name] invoice [Invoice #], [Month]. Good for a retainer, where the month tells the story.
• Deposit invoice [Invoice #] for [project name]. Say deposit up front, so nobody has to open it to know why it exists.
• Avoid "Quick question", "Hello" and "Following up" on a first send. They read like a message that can wait, and it gets waited on.

Six invoice email templates to copy

Replace the bracketed fields, delete what does not apply and keep the message short. These cover the first send only. For anything overdue, use the templates in how to ask for payment professionally.

Subject: Invoice [Invoice #] from [Your name], due [due date]

Hi [Client name],

Thanks again for choosing me for [project]. My first invoice is attached: [Invoice #] for [amount and currency], due on [due date] ([payment terms]).

Payment details are on the invoice. You can pay by [bank transfer / payment link]. If your accounts payable team needs a PO number, a different billing address or a particular format, tell me and I will reissue it the same day.

Could you reply to confirm it arrived and went to the right person? That saves us both a chase later.

Thank you,
[Your name]
[Business name]

Subject: Invoice [Invoice #] from [Your name], due [due date]

Hi [Client name],

Please find invoice [Invoice #] attached for [short description of the work], total [amount and currency].

It is due on [due date]. Payment details are on the invoice.

Let me know if anything needs changing.

Best,
[Your name]

Subject: [Business name] invoice [Invoice #], [Month]

Hi [Client name],

Attached is the invoice for [Month] under our [monthly retainer / support agreement]: [Invoice #], [amount and currency], due [due date].

It covers [what is included]. Anything outside the agreed scope is listed separately, with a short note.

The next invoice will follow on [date], on the same terms.

Thank you,
[Your name]

Subject: Deposit invoice [Invoice #] for [project name]

Hi [Client name],

As agreed in our proposal, here is the [deposit / milestone: milestone name] invoice for [project name]: [Invoice #], [amount and currency], due [due date].

Work on [next phase] begins once it is paid, so the dates we discussed hold. The amount is credited against the final invoice.

If your team prefers to pay in a different way, reply and I will adjust the payment details.

Thank you,
[Your name]

Subject: Invoice [Invoice #] from [Your name], due [due date] ([currency])

Hi [Client name],

Please find invoice [Invoice #] attached, total [amount] [currency], due on [due date].

To pay by bank transfer, use the IBAN and SWIFT/BIC shown on the invoice and quote [Invoice #] as the reference. Please send the full amount in [currency] and choose the option where the sender covers bank charges, so the amount I receive matches the invoice.

[Optional, only if it applies: The invoice is issued without VAT. Please check with your accountant whether the reverse-charge mechanism applies to your purchase.]

Tell me if your finance team needs a tax ID, a PO number or another format.

Thank you,
[Your name]
[Business name]

Subject: Invoice [Invoice #], due in [X] days

Hi [Client name],

Invoice [Invoice #] for [amount and currency] is attached again for your records. It is due on [due date], in [X] days.

Payment details are on the invoice. If it has already gone into your payment run, thank you, and please ignore this.

Best,
[Your name]

When to send it

Send it when the work is done or when the agreed milestone is reached, not at the end of the month by habit. The clock on your payment terms starts at the invoice date, so every day you wait is a day you finance the client's project. For time-and-materials work, send on the schedule in your contract. You will find advice about the best weekday or hour to send. Treat it as convention, not fact: the better rule is to send on a working day, in the client's business hours, to the person who pays.

What happens after you send

Sending is not the end of the job. Three small habits remove most of the uncertainty.

• Confirm receipt. Ask for a short reply, or check that the email did not bounce. If the client does not answer, a message to the accounts payable contact is reasonable.
• Know if it was seen. An attachment tells you nothing. With QuickBilling's share links, the invoice records when the link is opened, which you can review under analytics. The payer can also mark the invoice paid from the link.
• Schedule a reminder. In QuickBilling, customer reminders are opt-in on each invoice and only apply to invoices sent through QuickBilling email. If you send another way, put the date in your calendar.

The Free plan includes five share links a month, which is enough to try the habit. Details of the features are on the invoicing page and the analytics page.

Common mistakes

• Sending to your project contact when only accounts payable can release payment. Ask once, early, who that is.
• A PDF named invoice.pdf. The client's fifth invoice from you becomes unfindable.
• Payment details only inside the attachment. Put the due date and the amount in the email body too.
• No IBAN or SWIFT/BIC on an international invoice, then a vague bank transfer that arrives short after fees.
• Calling a PDF or a share link an e-invoice and assuming it satisfies a client's e-invoicing requirement. Ask what format they actually accept.
• Changing an invoice after sending without a new number or a credit note. Duplicate numbers get flagged by accounting systems.
• Treating a receipt as an invoice, or the reverse. If you are unsure of the difference, see invoice vs receipt vs bill vs estimate.
• Waiting for the due date to follow up. The scheduled reminder in step five exists for this.