What Is a Payment Gateway?
If you're asking what a payment gateway is, here's the short answer: it's the technology service that connects your online store, app, or checkout system to banks and card networks to authorize a payment in seconds. When a customer pays with a card, the gateway encrypts the data, sends it to the relevant bank, receives an approval or decline in real time, and hands that response back to you — without your business ever having to handle the customer's raw card number.
In short, a payment gateway is the intermediary that makes it possible to accept payments online securely, whether by credit card, debit card, bank transfer, or a digital payment method. Without a payment gateway, accepting cards on a website would require a direct connection to every bank, something no mid-size business builds on its own.
How a Payment Gateway Works, Step by Step
The flow of a payment gateway transaction follows the same logic regardless of which provider you use:
- The customer enters their card details or picks a payment method on your site or app.
- The gateway encrypts that data and sends it to the payment processor.
- The processor forwards it to the card network (Visa, Mastercard, American Express).
- The network checks with the card's issuing bank whether there are funds and whether the transaction is valid.
- The issuing bank responds with an approval or a decline.
- The response travels back through the same chain to the gateway, which shows it to your customer and your system.
- One or several days later, the acquiring bank deposits the funds into your account, minus its fee.
This entire round trip happens in a matter of seconds, even though it involves four or five different parties: your business, the gateway, the processor, the card network, and the two banks (issuing and acquiring). Once a payment is approved, the next step in Mexico is usually a fiscal one: you need to issue the corresponding CFDI through your electronic invoicing system, and if the customer ends up paying by bank transfer instead of card, you also need to issue the matching payment complement.
Payment Gateway vs. Payment Processor: What's the Difference?
These two terms get mixed up often because the same provider usually offers both. A payment gateway is the layer that captures and encrypts payment data at the point of sale or checkout; a payment processor is what actually moves the money between the banks involved. Companies like Stripe or Conekta act as both at once: they provide the gateway (the payment form, the encryption, the integration) and also process the transaction behind the scenes. For a business that's simply choosing a provider, this distinction rarely changes the decision, but it does explain why some contracts talk about "processing" and others about a "gateway" to describe the same underlying service.
What Determines the Cost of a Payment Gateway
There's no single fee that applies across the market: every payment gateway sets its own pricing based on several factors, and any specific number depends on the contract you negotiate with the provider. The factors that influence pricing the most include:
- The payment method accepted. Credit card transactions almost always cost more than debit or bank transfer, because card networks charge differently depending on the type of card.
- Your monthly transaction volume. Providers typically offer better rates to businesses processing more transactions per month, the same way volume pricing works for most services.
- Your industry. Some sectors are considered higher risk for fraud or chargebacks (travel, digital subscriptions, gambling), and that risk shows up in the fee.
- Domestic vs. international cards. Processing a card issued outside Mexico usually costs more than processing a Mexican-issued card.
- Add-on services. Fraud prevention, tokenization, recurring billing, or payment links can carry a separate cost on top of the base per-transaction percentage.
- Flat fees. Some providers charge a flat fee per transaction in addition to the percentage, others charge only a percentage; it's worth reviewing the full fee schedule, not just the headline number.
Before signing with any gateway, ask for the complete fee schedule and compare it against your actual volume and type of sales, not the generic example on the provider's marketing page.
Payment Gateways in Mexico: Main Options
The Mexican market has several established payment gateways, each with a different focus:
- Stripe. Popular among digital and SaaS businesses for its technical documentation and ease of API integration; it operates in Mexico and accepts both domestic and international cards.
- Conekta. A Mexican payment gateway built for the local market, with support for cards, cash payments at convenience stores, and SPEI bank transfers, plus built-in invoicing.
- Mercado Pago. The payment gateway inside the Mercado Libre ecosystem, useful for businesses already selling on that marketplace or looking for a digital wallet with reach across Latin America.
- OpenPay. Owned by BBVA México, aimed at businesses that want an integration backed by an established bank in the country, with support for cards, cash payments, and direct debit.
Each one has its own onboarding process, documentation requirements, and deposit timelines, so it's worth comparing at least two before integrating one into your business.
Security and PCI DSS Compliance for a Payment Gateway
Any business that processes, stores, or transmits card data needs to comply with PCI DSS (Payment Card Industry Data Security Standard), a set of security requirements defined by the major card brands to protect cardholder information. For most businesses, using a certified payment gateway is the most practical way to operate within that standard: the gateway absorbs the heaviest part of the compliance burden because the card number never touches your own servers — it travels encrypted directly between the customer and the provider.
That doesn't remove all of your responsibility: you still need to be careful about how you integrate the payment form, what customer data you store, and how you protect access to your gateway dashboard. But it dramatically shrinks the scope of what your own business has to audit, compared to building a payment system from scratch.
Payment Gateway Examples by Business Type
How a business uses a payment gateway changes depending on the model:
- Online store: the site's checkout connects to the gateway to charge a card at the moment of purchase.
- Service business that collects payment through WhatsApp or social media: instead of a full checkout, it uses a payment link generated by the gateway, which the customer pays without leaving the chat.
- Subscriptions or memberships: the gateway stores a token for the card (not the actual number) to charge recurring payments every month without asking the customer for their details again.
- Physical point of sale with a digital option: a business that also wants to accept CoDi or SPEI transfers alongside cards, all from the same dashboard.
- Marketplace or multi-vendor platform: the gateway splits the payment between the platform and each vendor according to commission rules set up in advance.
How to Choose the Right Payment Gateway for Your Business
There's no single right answer, but these questions help narrow down the options:
- What payment methods do you need to accept besides cards (SPEI, CoDi, cash)?
- How easy is it to integrate the gateway with your current site, app, or point of sale?
- Does the provider offer real support and reasonable response times for your market?
- Do the deposit timelines to your account fit your cash flow?
- Does the gateway offer fraud-prevention tools that match your transaction volume?
When a business needs to accept payments across several channels — website, app, WhatsApp, point of sale — without integrating a separate gateway for each one, it's worth evaluating a multi-platform payments solution that centralizes all of those flows in a single dashboard, instead of connecting a different gateway per channel.
Frequently Asked Questions
What is a payment gateway in simple terms?
It's the service that connects your site or app to banks to authorize a charge by card or another digital payment method, encrypting the customer's data in the process so your business never has to handle it directly.
Is a payment gateway the same as a bank account?
No. The gateway doesn't hold your money: it authorizes and processes the transaction, and the final deposit lands in whatever bank account you registered with the provider, usually one or several days after the sale.
How much does a payment gateway cost in Mexico?
Cost varies by provider, payment method, volume, and industry, so there's no single figure that applies to every case; the right move is to request the fee schedule directly from the provider you're evaluating.
Do I need to know how to code to integrate a payment gateway?
It depends on the provider. Some offer no-code buttons or payment links, while a full checkout integration for a store usually does require development work, typically through an API.
What if my business already receives payments by SPEI transfer?
You can keep accepting direct transfers and add a payment gateway to accept cards too; many businesses in Mexico combine both methods. If you also want to confirm those transfers are real before shipping an order, it's worth reviewing how to validate a SPEI transfer with Banxico's CEP.
If your business needs to accept cards, SPEI, CoDi, and payment links from a single dashboard without integrating a separate gateway for each channel, at AISDC we build multi-platform payments solutions that connect your site, your app, and your sales channels with the payment providers that fit your business best.