How to invoice a client
A step-by-step guide to invoicing clients correctly — what every invoice should include, common mistakes, and how to get paid faster. Step 1: Confirm the agreement before invoicing. Make sure you and your client are aligned on the scope of work, rate, and payment terms before you send an invoice. A written estimate or contract makes invoicing straightforward. Step 2: Create a professional invoice. Include your business name and contact information, the client's name and billing address, a unique invoice number, the invoice date, the payment due date, itemized line items with clear descriptions and amounts, payment terms (such as Net 15 or Net 30), and payment instructions. Step 3: Send it immediately. Invoice as soon as the work is done or a milestone is reached. The sooner the invoice arrives, the sooner it gets paid. Step 4: Follow up if it's overdue. Send a polite reminder 1–3 days after the due date. If there's still no payment after a week, send a firmer follow-up. Online card payments: clients can pay eligible invoices online by card when you connect your Square account to Duevero. The invoice includes a secure payment link they can open in any browser.