How to Send an Invoice: Step-by-Step (Email, PDF, Invoicing Software) Plus Templates and Follow-Ups

To send an invoice: create the invoice with your business details, the client's details, a unique invoice number, date, itemised services or products, totals, taxes, payment terms and payment methods; save it as a PDF or create it in invoicing software; then email it to the right contact with a short, polite message and a payment link. Track it and send reminders if it's not paid by the due date.

Step 1: Gather the details

• Your business name, address, contact, tax/registration number (if applicable)
• Client name, company, billing address, contact person, purchase order (PO) number if they use one
• Description of work or products, quantities, rates
• Agreed payment terms (e.g., due on receipt, Net 15, Net 30)

(Full list: What does an invoice look like?)

Step 2: Create the invoice

Give each invoice a unique, sequential number (see What is an invoice number?).

Step 3: Send it by email

• Send to the billing contact (ask clients who handles invoices)
• Attach a PDF or include a link from your software
• Use a clear subject line: "Invoice #1045 from Bright Studio – due 30 Nov"
• Include a payment link and bank details if applicable

Example invoice email

Subject: Invoice #1045 – Website design (due 30 November)

Hi Priya,

Thanks again for working with us. Please find attached invoice #1045 for $2,400 for the website design project, due on 30 November.

You can pay online here: [payment link]. Bank transfer details are on the invoice.

Let me know if you have any questions.

Best regards, Sam

Step 4: Track and follow up

• Software shows when invoices are viewed and paid
• Send a friendly reminder a few days before or on the due date
• Follow up after the due date at 3, 7 and 14 days with increasing firmness
• Call for significantly overdue invoices
• Apply late fees only if agreed in your terms

Example reminder

Hi Priya, a quick reminder that invoice #1045 ($2,400) was due on 30 November. You can pay here: [link]. If it's already been paid, please ignore this message. Thanks!

Tips to get paid faster

• Invoice immediately when work is done or on milestones
• Clear payment terms agreed before starting
• Multiple payment options (card, bank transfer, UPI, wallets)
• Deposits for larger projects
• Automatic reminders
• Accurate details (PO numbers, correct contact) to avoid delays in client approval processes

Automating invoices

• Recurring invoices for retainers and subscriptions
• Auto-reminders for overdue invoices
• Generate invoices automatically from bookings, completed jobs or CRM deals
• Sync payments to accounting
• Use automation tools (Zapier, Make, n8n) to connect systems (see Accounts payable automation for the payer side and How to automate business processes)

Frequently asked questions

How do I send an invoice?

Create an invoice with your details, client details, invoice number, date, itemised charges, totals, terms and payment options, then email it as a PDF or via invoicing software with a payment link.

How can I send an invoice through email?

Attach a PDF invoice or send it from invoicing software, use a clear subject with the invoice number and due date, include a short message and a payment link.

What should I write in an email when sending an invoice?

A greeting, the invoice number, amount, due date, what it's for, how to pay (link or bank details) and an offer to answer questions.

What is the best way to send invoices?

Invoicing software is best for most businesses because it tracks views and payments, offers online payment and sends automatic reminders.

When should I send an invoice?

Immediately after delivering the work or product, or at agreed milestones or billing dates.

How do I follow up on an unpaid invoice?

Send polite reminders before and after the due date, then firmer follow-ups and a phone call if it's significantly overdue.