HOW TO GUIDES

How to Send an Invoice to a Client: Best Practices That Get You Paid Faster

IBBy InvoiceBolt Editorial

July 7, 2025

6 min read

You did the work. You delivered the project. Now you need to get paid. But sending an invoice is not just attaching a PDF to an email and hoping for the best. How you send your invoice, when you send it, and what you write in that email directly affects how quickly money lands in your account. This guide covers everything you need to know to get paid faster and more consistently.

Why How You Send an Invoice Matters

Late payments are one of the biggest cash flow problems freelancers and small businesses face. Research consistently shows that invoices sent with clear payment terms, professional formatting, and a timely follow-up system get paid significantly faster than those that do not. The invoice sending process is not just admin, it is a direct part of your client relationship and your income reliability.

PRO TIP:Studies show that invoices sent within 24 hours of completing work are paid faster than those sent days or weeks later. Make it a habit to invoice immediately after delivery.

How to Send an Invoice by Email

Email is the most common and professional way to send an invoice. Never paste invoice details into the body of an email. Always attach the invoice as a PDF so it is easy to print, forward to accounts departments, and file properly.

Follow these steps every time:

Generate your invoice as a PDF using a tool like InvoiceBolt.
Write a clear, professional subject line that includes the invoice number and your business name.
Write a brief, polite email body that states the total amount and due date.
Attach the PDF invoice.
Send from a professional email address, not a personal one.

PRO TIP:If your client has a dedicated accounts payable email address or purchase order number, always include these in your invoice email. Missing these details is one of the most common reasons invoices get delayed in large companies.

What to Write in the Invoice Email Body

Keep your invoice email short and professional. Here is a ready to use template:

// EMAIL TEMPLATE 1
Subject: Invoice [INV-001] from [Your Business Name]

Hi [Client Name],

Please find attached invoice [INV-001] for [service description] completed on [date].

The total amount due is [amount], payable by [due date].

Payment can be made via [payment method: bank transfer, PayPal, etc.].

Please do not hesitate to get in touch if you have any questions.

Kind regards,

[Your Name]
[Your Business Name]
[Your Contact Details]

PRO TIP:Always mention the due date in the email body itself, not just on the invoice. Clients often skim emails without opening attachments, so having the key details visible immediately removes any excuse for missing the deadline.

Best Time to Send an Invoice

Timing matters more than most people realize. Sending your invoice on a Friday afternoon means it sits unread over the weekend and gets buried under Monday morning emails. Send invoices on Tuesday, Wednesday, or Thursday morning between 9am and 11am in your client's time zone for the highest open and action rates.

For recurring clients, establish a consistent invoicing day, for example every Friday or on the first of the month, so they know to expect it and can plan their payments accordingly.

PRO TIP:For international clients across different time zones such as UAE, UK, or Australia, schedule your invoice email to arrive during their morning work hours using a scheduled send feature in Gmail or Outlook.

How to Follow Up on an Unpaid Invoice

Even with the best invoice, some clients pay late. A structured follow up system removes the awkwardness and gets results. Here is a simple timeline:

3 days before due date: send a gentle reminder with the invoice attached.
On the due date: if unpaid, send a polite check-in.
3 days after due date: send the first formal follow up.
7 days after due date: send a firmer reminder.
14 days after due date: consider a phone call or formal late payment notice.

Here is a ready to use follow up email template:

// EMAIL TEMPLATE 2
Subject: Friendly Reminder: Invoice [INV-001] Now Overdue

Hi [Client Name],

I wanted to send a quick, friendly reminder that invoice [INV-001] for [amount] was due on [due date] and remains outstanding.

Could you please let me know when we can expect payment, or if there is anything on your end that needs resolving?

I have attached the invoice again for your reference.

Thank you for your time, I really appreciate it.

Kind regards,

[Your Name]

PRO TIP:Always stay polite in follow up emails, no matter how frustrated you feel. A firm but warm tone preserves the client relationship and is more likely to result in payment than an aggressive message.

Invoice Payment Terms That Get You Paid Faster

Your payment terms directly influence how quickly you get paid. Common options include:

Due on Receipt: payment expected immediately on receiving the invoice. Best for new clients or one-off projects.
Net 7: payment due within 7 days. Good for smaller amounts or regular clients.
Net 14: payment due within 14 days. A balanced option for most freelancers.
Net 30: payment due within 30 days. Standard for larger corporate clients.

Always state your payment terms clearly on the invoice itself and in the email body. Vague terms like "payment due soon" are a direct cause of late payments.

PRO TIP:If you frequently deal with late payments, consider adding a late payment clause to your invoices: "A late payment fee of 2% per month will be applied to invoices unpaid after [due date]." Even if you never enforce it, it encourages clients to pay on time.

Common Mistakes When Sending Invoices

Sending invoices late after completing the work.
Using a personal email address instead of a professional one.
Not including a unique invoice number making it hard to track and reference.
Forgetting to attach the actual invoice PDF.
Not specifying accepted payment methods.
Sending to the wrong contact instead of the accounts payable department.
Not following up at all when payment is overdue.

PRO TIP:Before hitting send, run through a quick checklist: correct client name and email, invoice attached as PDF, invoice number included, due date clearly stated, payment method listed. Thirty seconds of checking saves days of chasing.

Tools That Make Invoicing Faster

Manual invoicing in Word or Excel is slow, error-prone, and unprofessional. A dedicated invoice generator like InvoiceBolt lets you create a complete, professional invoice in under two minutes. Fill in your details once, add your line items, choose your currency from 38 options including GBP, AED, PKR, and USD, apply VAT or GST if needed, and download a clean PDF instantly. No account needed, no monthly fees, completely free.

Create and Send Professional Invoices Free at InvoiceBolt →