What is a payment gateway?

What is a payment gateway?

More and more businesses sell online, and almost all of them face the same question at some point: how do I receive my customers' money safely? In most cases, the answer involves a payment gateway, the service that processes online payments securely by connecting the store, the bank and the customer's card. Without one, taking card payments through a website would be slow, insecure and almost impossible to scale.

This article explains what a payment gateway is, how an online payment works step by step, what a business needs to start accepting online payments, how much the service costs, how it protects customers' data and how it differs from a payment button or a payment link.

What exactly is a payment gateway

A payment gateway is a technology service that acts as an intermediary between a business's website or app and the financial system. When a customer pays with a card, the gateway receives the card details, protects them with encryption and sends the payment request to the relevant bank so it can approve or decline the transaction. It then sends the response back to the store and, if the payment is approved, arranges for the money to reach the business's bank account.

A simple way to understand it is to compare it with the point-of-sale terminal in a physical store. In a shop, that terminal reads the card, talks to the bank and confirms the payment within seconds. Online, the payment gateway does the same job, except that the data travels encrypted over the internet instead of through the cable of a physical device.

Several parties take part in every online payment:

• The customer: the person who pays with a credit or debit card, or with a digital wallet.
• The business or seller: the party offering the product or service that wants to receive the money from the sale.
• The payment gateway: the service that transmits information securely among all the participants.
• The issuing bank: the institution that issued the customer's card and decides whether the payment is approved.
• The business's bank or processor: the institution that receives the money on behalf of the seller and deposits it into the seller's account.

How an online payment works step by step

Even though it looks instant to the customer, every online purchase involves a sequence of steps that is completed in a few seconds:

1. The customer pays: the shopper chooses the product, reaches the checkout screen and enters the card details (number, expiry date and security code) or chooses to pay with a digital wallet.
2. The gateway encrypts the data: the information is encoded right away using encryption protocols, so nobody can read it while it travels across the internet.
3. Authorization is requested: the gateway sends the payment request to the card's issuing bank through the processor or the business's bank.
4. The bank responds: the issuing bank checks that the card is valid, that it has enough funds or credit and that the transaction does not look fraudulent; then it approves or declines the payment.
5. Confirmation arrives: the gateway reports the result to the store and the customer immediately. If the payment is approved, the order is confirmed; if it is declined, an error message is shown.
6. The money is deposited: within a period that usually ranges from one to three business days, the sale amount, minus fees, is transferred to the business's bank account.

For the customer, the whole journey takes a few seconds and ends with a confirmation screen. Behind the scenes, the gateway makes sure the data travels protected and that every transaction is recorded and easy to reconcile.

Examples of well-known payment gateways

There are dozens of payment gateways around the world, and many of them are brands that shoppers themselves recognize when they pay. Some well-known examples:

• PayPal: one of the oldest and most widespread in the world; it works as a digital wallet and lets businesses charge cards without the buyer sharing card details with the seller.
• Stripe: a gateway aimed at businesses and developers, very common in online stores thanks to its easy integration and its recurring-billing tools.
• Mercado Pago: the payments platform linked to the Mercado Libre ecosystem, very popular in Latin America; it supports card payments, QR codes and payment links.
• Other options: there are also local gateways, services offered by banks themselves and international platforms such as Adyen or Square, each with different coverage, currencies and fees.

The provider's name usually appears on the payment screen, although many stores show their own brand during the purchase and the gateway is only identified when the customer enters the card details.

What a business needs to accept online payments

Setting up an online payment channel is easier than many people think. To start accepting cards, a business needs at least the following:

• A business bank account: it is the final destination for the money from sales. It can be a business account or, with some providers, a verified personal account.
• An agreement with a payment gateway: the business registers with the provider, submits its details and documents, and becomes enabled to receive payments.
• A sales channel: it can be a website with a shopping cart, a store on an ecommerce platform, an app or even a payment link sent by message.
• The integration: most gateways offer buttons, links, code snippets or plugins that connect the checkout to the site without building everything from scratch.

How long it takes to get started varies by provider and country: some enable the account within minutes, while others run a document review that can take several days. It is also worth checking which countries the gateway operates in, which currencies it accepts and whether it supports credit cards, debit cards, bank transfers or digital wallets.

How much payment gateways charge: fees

No gateway is free, because they all provide a financial and technology service that has real costs. The most common pricing model combines two elements:

• Per-transaction fee: a percentage of each sale that usually falls between 1% and 4%, depending on the card type, the country and the business's sales volume.
• Flat fee: many providers add a fixed amount per operation, in other words, a small charge for every payment processed.

Other costs can be added on top, such as monthly maintenance fees, setup charges or chargeback fees, which occur when a customer disputes a purchase and the bank returns the money. International and credit cards usually carry higher fees than local debit cards, and businesses with higher sales volumes can often negotiate lower rates.

Before choosing a provider, it is worth calculating what the fee represents on the business's average ticket, because a difference of one percentage point can add up to a significant amount at the end of the month.

Security: encryption and the PCI-DSS standard

The biggest fear of anyone selling online is that card data could fall into the wrong hands. That is why security is the heart of a payment gateway. Three elements are key:

• Data encryption: card information is encoded when it is sent using protocols such as SSL/TLS, so it cannot be read if it is intercepted along the way.
• Tokenization: instead of storing the real card number, the system keeps a code (token) that only the processor can interpret; this way, the business never holds complete sensitive data.
• Customer verification: protocols such as 3-D Secure require an extra confirmation (password, code or fingerprint) on risky purchases, which reduces card fraud.

In addition, the industry follows a worldwide standard called PCI-DSS (Payment Card Industry Data Security Standard), a set of security requirements that every company processing, storing or transmitting card data must meet. A major advantage of using a gateway is that most of that technical responsibility falls on the provider: the business avoids storing card numbers and dramatically reduces the risk of a data breach.

Payment gateway, payment button and payment link: differences

People often confuse three terms that are used almost as synonyms. The gateway is the infrastructure that processes the charge; the payment button and the payment link are ways to activate it without building a full shopping cart. Their main differences are summarized in the following table:

In practice, many gateways include all three formats: they offer full integration for large stores, buttons for simple pages and links for those who sell through social media or messaging without having a website.

Is a payment gateway right for any business?

If a business wants to sell online, a payment gateway is practically a requirement: it makes it possible to charge cards securely, accept orders at any time, reach customers in other cities or countries and reduce the risks of handling cash. Choosing the right provider, comparing fees, coverage and ease of integration, is the difference between a sales channel that runs on its own and a monthly headache.

One practical tip to close: whenever the provider offers it, open a trial account, run a couple of small real charges and verify that the money reaches the account within the promised time. That simple test says more than any sales brochure.