How to send an invoice to customers and get paid faster

Published Friday 5 December 2025

Table of contents

• Before you send an invoice
• What to include in your invoice
• How to invoice
• When to send an invoice
• Ways to send an invoice
• Tips for sending your invoice
• How to write an invoice email
• Track your invoices and payments
• Overdue payment reminder email (or call)
• The gentle reminder email you don't have to write
• Send invoices with confidence
• FAQs on sending invoices

Key takeaways

• Establish clear payment expectations upfront by discussing billing schedules, payment terms (typically 30 days), and accepted payment methods with customers before sending any invoices to prevent delays and disputes.

• Include all essential invoice elements such as unique invoice numbers, business and customer contact information, detailed descriptions of goods or services, itemized costs with taxes, and clear payment instructions to ensure professional and legally compliant billing.

• Send invoices immediately upon work completion rather than batching them monthly to maintain steady cash flow, and use email delivery with PDF attachments or online invoicing software for fastest, most secure transmission.

• Implement automated invoice tracking and payment reminder systems to monitor outstanding invoices in real-time and send polite follow-up messages without manual intervention when payments become overdue.

Before you send an invoice

Invoice preparation means setting clear expectations with your customer before sending any bills. This prevents payment delays and disputes.

Discuss these key points upfront:

• Billing schedule: When you'll send invoices (weekly, monthly, or upon completion)
• Payment terms: How long customers have to pay (typically 30 days). For VAT-registered businesses, you must normally issue a VAT invoice within 30 days of providing the goods or services.
• Payment methods: How customers can pay you

Clear expectations prevent surprises and speed up payments.

What to include in your invoice

Make sure every invoice you send includes these key details:

• Your business name and contact information
• Your customer's name and contact information
• A unique invoice number for your records
• The date you're sending the invoice and the payment due date

Then clearly show what you're charging for:

• A clear description of the products or services you provided
• The cost for each item, plus any taxes or discounts
• The total amount due
• Clear instructions on how to pay you
• Your business name and contact information
• Your customer's name and contact information
• A unique invoice number for your records. For tax purposes, you must keep VAT records for at least six years.
• The date you're sending the invoice and the payment due date
• A clear description of the products or services you provided
• The cost for each item, plus any taxes or discounts
• The total amount due
• Clear instructions on how to pay you

How to invoice

Creating an invoice involves adding essential information to an invoice template that legally requests payment for your work.

Include these required details:

• Invoice date and number: For tracking and legal purposes
• Business information: Your name, address, and contact details
• Customer details: Their name and billing address
• Description of work: Clear breakdown of goods or services provided
• Costs and taxes: Itemised pricing including any applicable VAT
• Payment instructions: Due date and how customers can pay

You can find more detail in the guide on how to make an invoice.

When to send an invoice

Invoice timing depends on your business model and helps maintain steady cash flow.

Send invoices at these key moments:

• Upon completion: When orders are filled or tasks finished
• Project milestones: For large projects, bill for work completed to date
• Recurring services: Monthly or quarterly for subscriptions and retainers
• Immediate delivery: For products shipped or services rendered

Cash flow timing affects your business stability. Sending all invoices on the same day creates uneven income patterns.

Problem: Monthly billing bunches create cash flow gapsSolution: Spread invoicing throughout the month

Strategies for smoother cash flow:

• Weekly billing: Send invoices every week instead of monthly
• Immediate invoicing: Bill as soon as work is completed
• Automated scheduling: Use software to spread invoice dates evenly

Ways to send an invoice

Getting your invoice to your customer is the final step. You have a few options, each with its own benefits.

• By email: This is the most common method. You can attach your invoice as a PDF to prevent it from being edited. It's fast, efficient, and gives you a digital paper trail.
• Through online invoicing software: Sending invoices directly from a platform like Xero is secure and professional. Your customer gets a link to a live invoice they can pay online instantly. You can also see when they've viewed it.
• By post: While less common now, sending a paper invoice might be necessary for some customers. It's slower and harder to track, but can feel more formal.

Tips for sending your invoice

• Call after you've sent your first bill
• Send your invoice in an uneditable format
• Take your billing completely online

Email delivery is the fastest and most reliable way to send invoices to customers.

Why email works best:

• Speed: Arrives instantly instead of days by post
• Reliability: Can't be lost in transit
• Accuracy: Email addresses are easier to verify than postal addresses

Always verify you're sending to the correct contact before hitting send.

Call after you've sent your first bill

Check they got your invoice and they understand what it's for. This simple follow up will show them you're serious about invoicing.

Send your invoice in an uneditable format

Scammers have intercepted emailed invoices and changed the bank account details. It'll be harder for them to do that if you send an online invoice, or PDF invoice.

Take your billing completely online

You can post your invoice securely online and send your customer a link. These online invoices allow your customer to pay straight away via a credit card, debit card, or an automated clearing house (ACH). Learn more about online invoicing.

How to write an invoice email

Invoice email subject lines determine how quickly your invoice gets processed by the customer's accounts team.

Effective subject line formats:

• With purchase order (PO): "Invoice 001 – PO ABC123 – due [date]"
• Without purchase order: "Invoice #001 - [Your Company] - Due [Date]"
• Project-based: "Invoice #001 - [Project Name] - Due [Date]"

Contact your customer's accounts payable team to confirm their preferred format.

You don't need an elaborate message in the body of the email. Stick with something simple, like: Here's [invoice number], from [company name], which is due on [due date]. Thanks so much for your business.

There will be a more detailed description of the goods or services on the invoice itself.

Track your invoices and payments

Sending the invoice is just the beginning. Keeping track of what's been paid and what's outstanding is key to managing your cash flow. Online accounting software makes this easy. You can see the status of all your invoices in one place – from sent and viewed to paid or overdue.

When a customer pays, your software can automatically match the payment to the right invoice, saving you time on admin. This gives you a real-time view of who owes you money, so you can follow up when needed.

Overdue payment reminder email (or call)

Overdue invoice follow-up is necessary because many invoices are paid late, and quick, polite action prevents customers from developing bad payment habits. If a payment is never made, you may eventually have to write off an invoice as a bad debt, which has its own set of rules.

Why prompt follow-up matters:

• Prevents delays: Early contact resolves payment issues faster
• Maintains relationships: Polite reminders preserve customer goodwill
• Establishes patterns: Quick responses train customers to pay on time

You can even email them before they're overdue with a message like:

"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."

If they've already gone past due, act quickly with a message like:

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

You can also call them:

You don't need to say a lot. Explain which invoice is late, then let them respond. A short, friendly call can often resolve things faster than email.

The gentle reminder email you don't have to write

Automated invoice reminders eliminate the stress of chasing overdue payments by handling follow-ups automatically.

How automation works:

• Payment tracking: Software monitors your bank for incoming payments
• Automatic matching: Links payments to specific invoices
• Scheduled reminders: Sends pre-written emails when payments are overdue
• Escalation alerts: Notifies you only when multiple reminders are ignored

This saves time and reduces the awkwardness of payment conversations.

Send invoices with confidence

Invoice timing directly impacts your cash flow. The faster you send invoices, the sooner you get paid.

• Send immediately: Invoice as soon as work is completed
• Follow up promptly: Contact customers about overdue payments within days
• Use automation: Let software handle routine reminders and tracking

Ready to streamline your invoicing process? Try Xero for free and automate your invoice sending, tracking, and payment reminders in one simple platform.

FAQs on sending invoices

We answer some common questions about sending invoices.

What does it mean to send an invoice?

Sending an invoice means sending a bill to your customer for products you've sold or services you've provided. It's a formal request for payment.

How do you send someone an invoice?

You can email it as a PDF, send it through online accounting software for instant payment, or mail a paper copy. Online software is often the fastest and most secure way.

How should you word an invoice email?

Keep your email clear and simple. The subject line should include the invoice number and your business name. The body can be a brief note, like: "Here's my invoice for [service/product]. Thanks for your business."

When is the best time to send an invoice?

It's best to send an invoice as soon as the work is complete or the product is delivered. For ongoing projects, you can agree on a regular billing schedule, such as weekly or monthly.

What happens if a customer doesn't pay their invoice?

If an invoice becomes overdue, start by sending a polite reminder email. If you still don't hear back, a friendly phone call can be effective. Using software to send automatic reminders can also help you get paid without the awkward follow-up.