Payment Gateway

What is a payment gateway?

A payment gateway is the technology that securely transmits payment information from your client to the payment processor and bank. When a client clicks "Pay Now" on your invoice and enters their credit card, the payment gateway handles the transaction—verifying the card, checking for fraud, and moving the money to your account.

Think of it as the digital equivalent of the card reader at a store, but for online payments.

How payment gateways work

When a client pays your invoice online:

• Client enters payment info — Card number, expiration, CVV
• Gateway encrypts the data — Securely transmits to the payment processor
• Processor contacts the bank — Verifies funds and checks for fraud
• Transaction approved or declined — Response sent back in seconds
• Funds transferred — Money moves to your account (usually 1-3 business days)

Common payment gateways

Popular payment gateways include Stripe, Square, PayPal, and Authorize.net. Each has different fee structures, features, and supported payment methods. Most charge a percentage of each transaction (typically 2.5-3%) plus a small fixed fee.

Why it matters for invoicing

Adding a payment gateway to your invoices lets clients pay instantly online—no mailing checks or calling in card numbers. The easier you make it to pay, the faster you get paid. Most invoicing software integrates with major payment gateways so you can include a "Pay Now" button on every invoice.