Sending an Invoice Checklist

Before you start

An invoice only starts the payment clock once it reaches the right person in a form they can process. A perfect invoice sent to the wrong inbox is a delayed invoice. Before you send, make sure the document itself has already passed your accuracy check — sending is the last step, not the place to catch errors.

Have the customer's preferred billing contact, format and any portal details to hand. Larger customers often dictate exactly how invoices must reach them, and ignoring that is a common cause of stalled payment.

Confirm where and how to send

Work through how this particular customer wants to receive invoices:

• The correct billing email or accounts-payable address — not just your day-to-day contact
• Whether they require upload to a supplier portal instead of email
• Whether a purchase order number must appear before they will pay
• The format they accept — usually PDF rather than an editable file
• Any cc to your contact so they know to approve it

If a customer has ever said 'send it to accounts', honour that every time rather than relying on a single person to forward it.

Prepare the message that carries it

The covering email or portal note does real work. Make it count:

1. Put the invoice number and amount in the subject line
2. Attach the invoice as a PDF, not a link that might break
3. State the due date plainly in the body
4. Summarise what the invoice is for in one line
5. Include your payment methods and bank details
6. Give a name and contact for any query

A clear covering message means the recipient can approve and schedule payment without opening a back-and-forth with you.

Record that you sent it

Once it is gone, capture proof and set your follow-up:

• Save a copy of the exact invoice you sent
• Note the date, time and address you sent it to
• Keep the sent email or portal confirmation
• Diarise the due date and a reminder a few days before

This record settles the most common dispute of all — whether the invoice arrived. If a customer claims it never came, see what to do when a customer says they never got the invoice.

Common mistakes

These trip people up most often when sending:

• Wrong recipient — sending to a project contact who cannot authorise payment
• No PO on a portal job — the system rejects the invoice automatically
• Editable attachment — sending a file the customer can alter
• Vague subject line — 'invoice attached' with no number or amount
• No record — no proof of when or where it was sent

A consistent send routine fixes most of these. Our free invoice tools help you produce a clean PDF to attach, and if invoices keep going astray and ageing, a free debt appraisal can show where the delays start.