How to Send an Invoice: Steps, Email Tips & Timing

Published Tuesday 7 April 2026

Table of contents

• Before you send an invoice
• What to include in your invoice
• How to send your invoice
• Choose payment methods that work for you
• When to send an invoice
• How to write an invoice email
• Best practices for sending invoices
• What to do when invoices go unpaid
• Automate your invoice reminders
• Make invoicing simpler with smart software
• FAQs on sending invoices

Key takeaways

• Establish clear payment terms with customers before sending your first invoice, including when you'll bill, payment deadlines, and accepted payment methods to prevent surprises and speed up payments.
• Send invoices immediately after completing work or fulfilling orders, as faster invoicing leads to faster payment and better cash flow for your business.
• Use PDF format or secure online invoicing systems when sending invoices to prevent tampering and offer multiple payment options like credit cards and bank transfers to make it easier for customers to pay on time.
• Follow up on overdue invoices the day after the due date with a polite but direct message, and consider using automated reminder systems to save time and maintain consistent follow-up without awkward manual chasing.

Before you send an invoice

Setting payment terms upfront prevents billing surprises and speeds up payment. Before you send your first invoice, discuss these details with your customer:

• When you'll invoice: weekly, monthly, or when the job's done
• How long they have to pay: 14, 30, or 60 days
• How they can pay: bank transfer, credit card, or online payment

When customers know what to expect, they're more likely to pay on time.

What to include in your invoice

Every invoice needs specific information to look professional and get paid promptly. Include these essential details:

• Your business details: name, address, and contact information
• Customer details: their name, address, and any purchase order number
• Invoice number and date: use sequential numbering for easy tracking
• Description of goods or services: what you provided and when
• Costs and taxes: itemized prices plus any Goods and Services Tax (GST) or Harmonized Sales Tax (HST) you're required to charge
• Payment instructions: due date, accepted payment methods, and where to send payment

You can start with an invoice template or learn more in the guide on how to make an invoice.

How to send your invoice

Email is the fastest and most common way to send an invoice. It creates a digital record and allows your customer to pay online instantly. You can also send invoices through accounting software, which automates much of the process for you.

If you need to send a paper copy, use postal mail but be aware of potential delays. No matter the method, always confirm you have the correct contact person and address.

Choose payment methods that work for you

Offering multiple payment options makes it easier for customers to pay you on time. The right choice depends on your business and what's most convenient for your clients.

• Bank transfers are a common and secure method for business-to-business (B2B) transactions.
• Credit and debit cards are convenient for customers and can speed up payments, especially for online sales.
• Online payment services provide a simple way for clients to pay directly from the invoice.

Clearly state the accepted payment methods on every invoice.

When to send an invoice

Send invoices as soon as the work is done or the order is filled. The faster you invoice, the faster you get paid.

Common invoicing schedules include:

• On completion: send immediately when a job or order is finished
• Interim billing: invoice for work done to date on large projects
• Recurring invoices: bill at regular intervals for subscriptions or retainers

Consider your cash flow when scheduling invoices. If all your invoices go out on the same day, payments will arrive around the same time, creating peaks and valleys in your bank balance.

To smooth out cash flow:

• spread invoicing across the month rather than sending everything at once
• invoice weekly instead of monthly
• use software to send invoices automatically so timing is never missed

How to write an invoice email

An invoice email should be brief and clear. Include the key details your customer needs to process payment quickly.

Write a clear subject line

The subject line helps accounts payable teams find and process your invoice. Include:

• your company name
• the invoice number
• the purchase order number (if applicable)

Example: Invoice #1234 from [Your Company] Purchase Order (PO) #5678

Ask your customer's accounts team how they prefer subject lines formatted.

Keep the message simple

The email body doesn't need much detail. A short message works best:

Here's invoice #1234 from [Company Name], due on [Date]. Please let me know if you have any questions. Thanks for your business.

The invoice itself contains the full description of goods or services.

Best practices for sending invoices

Follow these best practices to protect your invoices and speed up payment:

• confirm receipt on your first invoice: Call your customer to check they received it and understand what it's for. This shows you're serious about getting paid.
• use Portable Document Format (PDF) or online invoice formats: Editable documents can be intercepted and altered by fraudsters who change payment details. PDFs and online invoices are harder to tamper with.
• offer online payment options: Send a secure link that lets customers pay immediately by credit card, debit card, or bank transfer. The easier you make it to pay, the faster the money arrives.

Always double-check you're sending to the right contact before hitting send.

What to do when invoices go unpaid

More than a third of invoices go past due, so you'll likely need to follow up at some point. Act quickly and politely to prevent late payment from becoming a habit.

Send a pre-due reminder

A gentle nudge before the due date can prompt payment:

Invoice [number] is due tomorrow. You should have everything you need to process it, but let me know if any questions come up.

Follow up immediately when overdue

Don't wait. Send a message the day after the due date:

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

Make a phone call for persistent delays

A call can feel awkward, but that's exactly why it works. Keep it simple: state which invoice is late, then let them respond. Don't fill the silence. Feeling uncomfortable motivates action on both sides.

Automate your invoice reminders

Automated invoice reminders save you time and reduce awkward follow-ups. Instead of manually chasing payments, let software handle the routine work.

An online invoicing system can:

• track all your invoices: see what's been sent, paid, and overdue in one place
• match payments automatically: the software watches your bank deposits and marks invoices as paid
• send reminders for you: when an invoice passes its due date, a pre-written email goes out automatically

You only need to step in when reminders are ignored. This frees up your time for the work that actually grows your business.

Make invoicing simpler with smart software

Getting paid starts with sending your invoice promptly. The sooner your customer has the bill, the sooner you can expect payment.

The right invoicing software makes the entire process easier. You can create professional invoices, send them instantly, offer online payment options, and automate reminders for overdue accounts. That means less time chasing payments and more time running your business.

Ready to simplify your invoicing? Get one month free and see how Xero can help you get paid faster.

If payments still aren't coming through, read the guide on chasing outstanding invoices.

FAQs on sending invoices

Here are answers to common questions about sending invoices and getting paid.

What's the best file format for sending invoices?

PDF is the most widely accepted format because it preserves your formatting and can't be easily edited. Online invoices sent via a secure link are even better, as they allow customers to pay immediately.

Should I send invoices on weekends or holidays?

Avoid sending invoices on weekends or public holidays when accounts teams aren't working. Invoices sent on Tuesday, Wednesday, or Thursday tend to get processed faster.

How long should I wait before sending a payment reminder?

Send your first reminder the day after the due date. Waiting too long signals that late payment is acceptable. A polite, prompt follow-up keeps your invoice top of mind.

Can I charge late fees if an invoice isn't paid on time?

Yes, but only if your payment terms include late fee details. State the fee amount or percentage clearly on your invoice and in your initial agreement. Check local regulations, as rules vary by province.

Do I need to keep copies of all sent invoices?

Yes, you must keep copies for tax and audit purposes. According to the Canada Revenue Agency, businesses must generally keep required records for a period of six years from the end of the last tax year they relate to. Cloud-based invoicing software stores records automatically, so you don't have to manage files manually.