How to send an invoice by email and get paid faster

Published Monday 30 March 2026

Table of contents

• Before you send an invoice
• How to invoice
• When to send an invoice
• How to send an invoice: Step-by-step
• Ways to send an invoice
• How to write an invoice email
• Getting paid faster
• Overdue payment reminder email (or call)
• The gentle reminder email you don't have to write
• Simplify invoicing with Xero
• FAQs on sending invoices

Key takeaways

• Establish payment terms upfront by discussing invoicing schedules, payment deadlines, and accepted payment methods with customers before starting work to avoid surprises and payment delays.
• Send invoices immediately after completing work or delivering goods, as faster invoicing leads to faster payment and better cash flow management.
• Use email with PDF attachments as your primary delivery method since it's instant, creates a clear record, and prevents invoice fraud through uneditable documents.
• Implement automated payment reminders through invoicing software to reduce manual follow-up work and improve payment processing times by up to 25%.

Before you send an invoice

Preparing your invoice starts before you create the bill. Discuss payment terms with your customer so nothing comes as a surprise.

Set out these details upfront:

• Invoicing schedule: when you'll send invoices (weekly, monthly, or when the job's done)
• Payment deadline: how long they'll have to pay
• Payment methods: how they can pay you

A customer should know when they'll need to part with their cash before they receive your invoice.

How to invoice

Creating an invoice involves adding your business details, itemising what you sold, and stating payment terms. Open an invoice template, date it, and add an invoice number.

Include these details:

• Your business information: name, address, and contact details
• Customer information: their name and billing address
• Goods and services: description of what you sold
• Costs: itemised prices including any taxes you're expected to charge
• Payment instructions: when and how to pay

You can get more information in our guide on how to make an invoice.

When to send an invoice

Send your invoice as soon as you've delivered the goods or completed the work. The faster you invoice, the faster you get paid.

Here's when to invoice based on your situation:

• One-time jobs: send immediately after completing the work
• Large projects: send interim invoices for work done to date
• Subscriptions or retainers: send recurring invoices at regular intervals
• Product orders: send when the order has been filled

Think about your cash flow when you create a billing schedule. Late payments can have a significant impact. A recent report found that 50% of businesses with many overdue invoices reported issues with cash flow. If you send all your invoices on the same day every month, your bank balance will be full of ups and downs.

To smooth out your cash flow:

• Invoice weekly rather than monthly
• Spread invoicing across the month instead of batching
• Use invoicing software to automate recurring invoices

How to send an invoice: Step-by-step

Sending an invoice takes just a few minutes once your invoice is ready. Follow these steps to deliver your invoice and start the payment clock.

1. Finalise your invoice: Double-check all details are correct, including amounts, dates, and payment terms
2. Choose your delivery method: Email is fastest, but online links or post may suit some customers better
3. Send the invoice: Attach the PDF to an email or share the online invoice link
4. Confirm receipt: For first-time invoices, follow up with a quick call or email to make sure it arrived
5. Track the payment: Log the invoice in your records and note the due date for follow-up

The sooner you send your invoice, the sooner you can expect payment. If you're using invoicing software, you can automate steps 3–5 and save time on every invoice.

Ways to send an invoice

There are three main ways to send an invoice: email, online invoicing software, or post. Choose the method that works best for your customer and your business.

Send invoices by email

Email is the fastest and most common way to send invoices. Your invoice arrives instantly, can't get lost in the post, and creates a clear record.

Follow these best practices:

• Double-check the recipient: confirm you're sending to the right contact
• Use PDF format: send invoices as PDFs so they can't be edited (this prevents fraud)
• Follow up on your first invoice: call to confirm they received it and understand the details

Send invoices online

Online invoicing lets your customer view and pay in one place. Post your invoice securely online and send your customer a link.

Benefits of online invoicing:

• Faster payment: customers can pay instantly via credit card, debit card, or bank transfer
• Better security: harder for fraudsters to intercept or alter
• Automatic tracking: see when invoices are viewed and paid

Send invoices by mail

Postal mail is slower but sometimes necessary. Some customers or industries require paper invoices for their records.

Use mail when:

• your customer specifically requests a paper invoice
• you're working with government agencies that require physical documentation
• you need to include physical materials with the invoice

How to write an invoice email

Your invoice email should be brief and include key details in the subject line. A clear subject line helps your customer's accounts payable team process your invoice faster.

Subject line example: Invoice #1234 from [Your Company] – Due [Date]

Ask your customer how they'd like the subject formatted. Some prefer a purchase order number included.

Email body example:

Hi [Name],

Here's invoice #1234 for [brief description], which is due on [date].

Let me know if you have any questions.

Thanks for your business.

[Your name]

Keep the email short. The invoice itself contains the detailed breakdown of goods or services.

Getting paid faster

The way you send an invoice affects how quickly you get paid. Small changes to your invoicing process can reduce payment delays and improve your cash flow.

Here's how to speed up payment:

• Offer online payment options: customers pay faster when they can click a link and pay by card or bank transfer
• Set clear payment terms: state the due date prominently and agree terms before you start work
• Send invoices immediately: the longer you wait to invoice, the longer you wait to get paid
• Use automatic reminders: set up pre-due and overdue reminders so you don't have to chase manually
• Make invoices easy to process: include purchase order numbers and send to the right contact

If faster cash flow is a priority, consider offering early payment discounts. For example, offer 2% off for payment within 10 days. Research shows this is the most effective way of getting cash into the bank ahead of the due date.

Overdue payment reminder email (or call)

Nearly 60% of invoices are paid late, so you'll likely need to follow up at some point. Be polite but act quickly to prevent late payments from becoming a habit.

Pre-due reminder (send one–two days before):

"Please remember that invoice #[number] is due tomorrow. You should have everything you need to process it, but let me know if any questions come up."

Overdue reminder (send immediately after due date):

"Invoice #[number] was due yesterday but we don't have any record of payment. Please let me know when I can expect payment."

Phone call approach:

A phone call can feel direct and personal, and that's exactly why it works. Keep it simple:

• State which invoice is late
• Let them do the talking
• Don't speak to fill the silence

The gentle reminder email you don't have to write

Invoice automation handles payment reminders for you.Online invoicing software tracks your invoices and sends follow-ups automatically, so you don't have to chase payments manually.

Here's how automated reminders work:

• Automatic tracking: the software monitors your invoices and bank deposits for matching payments
• Scheduled reminders: when an invoice is still unpaid on its due date, a pre-written email goes out automatically
• Exception handling: you only get involved when a customer needs personal attention

This handles payment follow-ups for you and helps you get paid faster, with research showing automation reduces payment processing times by 25%.

Simplify invoicing with Xero

Sending invoices and getting paid can be quick and simple. Xero's online invoicing helps you create professional invoices, send them securely, and set up automatic payment reminders, all in one place.

With Xero, you can:

• Create invoices quickly: use customisable templates with your branding
• Send invoices instantly: email or share a secure online link
• Accept online payments: let customers pay by card or bank transfer
• Automate reminders: set up automatic follow-ups for overdue invoices
• Track everything: see which invoices are paid, pending, or overdue

See how Xero can streamline your invoicing and help you get paid faster. Get one month free and try it yourself.

FAQs on sending invoices

Here are answers to common questions about sending invoices.

How do I send an invoice by email?

Attach your invoice as a PDF to an email, include the invoice number and due date in the subject line, and send it to your customer's accounts payable contact. Follow up with a phone call after sending your first invoice to confirm receipt.

What should I write in an invoice email subject line?

Include the invoice number, your company name, and the due date. For example: "Invoice #1234 from [Company Name] – Due 15 January." Ask your customer if they prefer a specific format, such as including a purchase order number.

Can I send an invoice before completing the work?

Yes. You can send a deposit invoice before starting work, or interim invoices for completed milestones on large projects. Make sure your payment terms are agreed upfront so the customer knows what to expect.

What's the best format to send an invoice in?

PDF is the safest format because it can't be easily edited, which protects against invoice fraud. Online invoice links are also secure and allow customers to pay immediately. Avoid sending invoices as Word documents or editable files.

How do I track which invoices I've sent?

Use a spreadsheet to log invoice numbers, dates, amounts, and payment status. For easier tracking, use invoicing software like Xero, which automatically monitors sent invoices and flags overdue payments.