With PayPal Invoicing you can send online invoices to customers, allowing them to pay instantly with their preferred payment method, even if they don't have a PayPal account. You can use it to keep track of all your invoices - paid and unpaid.

Here are some resources to get started with PayPal Invoicing:

• PayPal for Business App: Invoicing
• PayPal Developer: Create and Send Invoices
• Invoicing API
• How do I create and send an invoice?