Introduction to Online Payments
- Four players in every card payment: the customer, you, your acquirer, and the customer's issuing bank
- Authorization takes seconds. Settlement into your bank takes one to three days. They're separate steps
- A gateway carries the transaction. A processor moves the money. All-in-one providers do both
- You don't need to master any of this. Knowing it just means better questions and fewer surprises
Welcome to online payments. Here's how money gets from your customer's card to your bank account. And what you need to know to get paid on time.
Most of this happens automatically once you sign up with a provider. But the basics help. You ask better questions, spot problems faster, and avoid overpaying.
What You'll Learn
- The key players in a payment transaction.
- How money moves from your customer to your bank account.
- The difference between a payment gateway and payment processor.
What Happens When Someone Pays You
| Step | What Happens | How Long |
|---|---|---|
| 1. Customer taps "Pay" | Your processor sends card details to the card network | Milliseconds |
| 2. Authorization | Issuing bank approves or declines | 1-2 seconds |
| 3. Capture | You confirm the sale (automatic or manual) | Same day |
| 4. Settlement | Money transfers from issuer to your processor | 1-2 business days |
| 5. Funding | Your processor deposits into your bank account | 1-3 business days |
That's the whole flow. The rest of this guide explains each step and what to do when things go wrong.
The Payments Ecosystem
Every online transaction involves four key players:
| Player | Who They Are | What They Do |
|---|---|---|
| Customer | The person buying | Enters their card details |
| Merchant | You | Sells the product, receives the money |
| Acquirer (your processor's bank) | Your payment provider's bank | Deposits money into your account |
| Issuer (customer's bank) | Customer's bank (Chase, Citi, etc.) | Approves or declines the transaction |
Sign up with Stripe or Square, and they handle the acquirer relationship. You don't need a separate merchant account. A merchant account holds your card funds before they land in your regular business account. All-in-one providers include one automatically.
The Flow of a Transaction
Here's what happens when a customer clicks "buy":
You don't need to memorize this. But payments fail and money goes missing. This is how you figure out where it got stuck.
- The customer enters their payment details on your checkout page.
- That information goes to your payment gateway.
- The gateway passes it to the payment processor.
- The processor routes it to the card networks: Visa, Mastercard, and the rest.
- The network asks the customer's bank whether to approve the transaction.
- The approval or decline travels back through the chain. Your website notifies the customer.
- If approved, the funds move from the issuer to your merchant account. That's settlement, and it usually takes 1-2 business days.
The whole thing takes a few seconds.
A payment gateway collects card details. A payment processor moves the money between banks. Stripe, Square, and Shopify Payments bundle both into one service, so you don't set them up separately. You'd only deal with a standalone gateway on a traditional merchant account. Those usually start at $500K+/month.
What This Means for Your Business
A few practical takeaways:
- You get paid in 1-3 days, not instantly. Authorization is immediate, but the money takes time to settle into your bank.
- Declines happen. About 10-15% of transactions get declined. Some you can recover, some you can't.
- Every step costs money. The card networks, issuing banks, and your processor all take a cut. That's why fees exist.
- Problems usually trace back to one player. When something goes wrong, this flow tells you who to call.
Your One Action
Pick a processor and create a free account. You can run a test payment in under 15 minutes.
- Selling online? Start with Stripe or Square.
- On Shopify? Use Shopify Payments. Processing elsewhere adds a Shopify gateway fee on every order. That's 2% on Basic, 1% on Grow, 0.6% on Advanced, 0.2% on Plus (shopify.com/pricing, verified 2026-08-02).
- Retail/in-person? Start with Square at 2.6% + 15c with a free reader. Helcim runs interchange + 0.40% + 8c with no monthly fee. Cheaper, but the statement takes more reading.
- Not sure? The next lesson compares them with published rates and sources.
What You'll Need to Get Started
Most providers approve you in minutes. Here's what to have ready:
- A bank account for deposits
- Tax ID / EIN (or SSN for sole proprietors)
- Business address and website (or social media page)
- A product or service to sell
- About 15 minutes for signup