Payment Gateways Explained: How They Work and How to Choose One

Payment gateways are the technology that lets your store accept card and wallet payments securely, but they are only one link in a longer chain. Between a customer tapping "Pay" and money landing in your bank account, the transaction passes through several parties, each with its own fees and rules. Understanding that chain helps you choose the right provider, read its contract, and avoid surprises in fees, delayed payouts and disputes. This article is part of The Complete Guide to Starting a Successful Online Store.

Who is involved in a payment

• Cardholder: the customer who pays.
• Issuer: the customer's bank, which issued the card and approves or declines the transaction.
• Card scheme: networks such as Visa and Mastercard, plus local networks such as mada in Saudi Arabia, KNET in Kuwait and Meeza in Egypt. They carry transaction messages between banks and set the rules.
• Acquirer: the bank that contracts with the merchant to accept cards, receives funds from the network and pays them to you, and carries part of the risk of your business.
• Payment gateway: the technical front end that captures payment details securely and sends them for processing. Think of it as the card terminal of an online store.
• Processor: the party that routes transaction messages between the gateway, the networks and the banks. It is often part of the acquirer or of the payment provider itself.

Aggregators: everything in one contract

Most small and mid-sized stores do not contract with an acquiring bank directly. They sign with a payment facilitator (an aggregator) that bundles gateway, processing and acquiring, and onboards you as a sub-merchant under its master account. Activation is faster and needs fewer documents. In return you have less room to negotiate fees, and you are subject to the provider's risk policies, including holds on funds. Examples of providers operating in the region include PayTabs, Tap Payments, HyperPay, Moyasar, Paymob and Checkout.com. They are named for illustration, not as recommendations, and coverage and features vary by country and change over time.

A payment, step by step

1. The customer enters card details on the payment page: either a page hosted by the provider, or fields embedded in your store and managed by the provider.
2. The gateway encrypts the data and sends it to the processor.
3. The customer is asked to verify their identity through 3-D Secure, if it is enabled.
4. The network passes the request to the issuer, which checks the balance and its fraud rules, then approves or declines.
5. The response comes back within seconds, and your store confirms the order or shows the decline.
6. The amount is captured immediately or later, depending on your settings.
7. In the settlement cycle, the acquirer receives the funds, deducts fees and pays the net amount into your account.

Authorization and capture

Authorization reserves the amount on the customer's account without taking it. Capture actually takes the reserved amount. Most stores do both at once, but separating them helps when you need to confirm stock, make products to order, or charge at dispatch. Be aware that an authorization expires automatically after a period set by the issuer and the network. If you do not capture before then, you may need to ask the customer to pay again.

3-D Secure

3-D Secure is a step in which the issuer checks that the cardholder is the one paying, through a one-time code sent by SMS or an approval in the banking app. Version 2 of the protocol (3DS2) sends more data about the transaction and device, so the bank can approve low-risk payments without asking the customer to do anything extra.

• Benefit: it reduces fraud with stolen cards, and for authenticated transactions, liability for fraud-related chargebacks generally shifts from the merchant to the issuer, subject to network rules and conditions.
• Cost: an extra step that can fail, such as a code that never reaches an international number, or a bank page that works poorly on mobile. When it fails, the order is lost.

In many markets the acquirer or regulator requires it, and your provider will tell you if it is mandatory in your case. Track the share of transactions that fail at this particular step: it is one of the causes of lost orders covered in Cart Abandonment.

Settlement: when does your money arrive?

An approved transaction does not mean the money is in your account. Transactions are batched and settled on cycles the provider sets: daily, weekly, or after a fixed number of business days. First payouts for new accounts may be delayed while the provider reviews your business, and some providers hold back a share of sales for a set period as protection against refunds and chargebacks (a rolling reserve), especially in higher-risk categories or for products delivered long after purchase.

So reconcile every payout against its orders. Illustrative weekly payout: card sales of SAR 10,000, minus a SAR 400 refund, minus transaction fees under your contract, minus any reserve held, leaves the net amount paid to you. If you do not reconcile weekly, you will find errors months later. Ask your provider for a detailed, exportable settlement report, and confirm the payout currency and whether any currency conversion applies.

Fee structures: what to ask about

Numbers differ between providers and change over time, but the structures are similar. What matters is knowing which ones apply to you:

• A percentage of each transaction, sometimes with a fixed fee per transaction on top.
• Different rates by card type: local cards are often cheaper than international ones, and corporate or foreign-issued cards may be priced differently.
• Setup and monthly fees, if any.
• Refund fees: some providers do not return the original transaction fee when you refund a customer.
• Chargeback fees: a charge for each dispute opened, sometimes regardless of the outcome.
• Currency conversion and payout fees.

Compare costs against your real sales pattern. A store with many small orders feels fixed fees far more than one with a few large orders.

Refunds and chargebacks

A refund is your decision: you return the money to the customer through the same payment method, and how long it takes to show on their statement depends on their bank. A chargeback starts with the customer, through their bank. The bank pulls the amount back from you provisionally, you are usually charged a fee, and you get a limited window to respond with evidence.

Common chargeback reasons: a transaction the customer does not recognize, an item that never arrived, an item not as described, a duplicate charge, or a subscription that was not canceled. The evidence you need: order details, proof of delivery (a signature, delivery code or photo), your correspondence with the customer, the returns policy they accepted, and the 3-D Secure result.

To prevent them:

• Make your store name on the customer's card statement (the billing descriptor) clear and instantly recognizable.
• Reply to complaints quickly, and refund voluntarily when the customer is right. A refund costs less than a chargeback.
• Keep proof of delivery, and publish a clear returns policy as described in Shipping, Delivery and Returns.

Cash on delivery vs. card payments

In markets where customers are used to cash on delivery, do not pick one and drop the other; manage both. Confirm COD orders on WhatsApp before dispatch, consider a small COD fee or a maximum order value, and encourage prepayment with a clear benefit such as faster shipping. Some couriers also offer card payment at the door, a useful middle ground.

Wallets and buy now, pay later

• Card wallets: such as Apple Pay and Google Pay. They replace the card number with a token and cut mobile checkout down to a tap. They need support from your provider, and you may need to verify your store's domain.
• Local wallets and instant payments: such as mobile wallets and the InstaPay network in Egypt. Some providers support them, and they can matter for customers who do not use cards.
• Buy now, pay later (BNPL): such as Tabby and Tamara in the Gulf and valU in Egypt. The provider pays you the order value minus its fee and collects the instalments from the customer. It can raise average order value in some categories, but merchant fees are usually higher than for cards, so build them into your margin.

Choosing a provider: questions to ask before signing

1. Which payment methods are supported in my country specifically: local cards, Apple Pay, BNPL?
2. Does it integrate officially with my store platform? See Choosing an E-commerce Platform.
3. What is the complete fee structure, including refunds, chargebacks and currency conversion?
4. What is the settlement cycle? Is there a reserve? In which currency are payouts made?
5. What documents are needed for activation, and is my business in a restricted category?
6. Is the payment page available in Arabic, and does it work well on mobile? Can cards be saved securely?
7. What fraud tools are available, and how is 3-D Secure configured?
8. Are reports detailed and exportable for reconciliation?
9. Is support available in Arabic, and will they help with chargeback responses?
10. How long is the contract, how do I exit, and can saved cards move with me to another provider?

Common mistakes

• Comparing on the percentage alone and ignoring fixed, refund and payout fees.
• Not testing checkout on mobile with cards from several different banks before launch.
• An unclear billing descriptor that leads customers to dispute a charge they do not remember.
• Storing card details in your store, or collecting them over WhatsApp. Leave that to a provider that complies with the Payment Card Industry Data Security Standard (PCI DSS), and see Online Store Security and Customer Data Protection.
• Not reconciling payouts against orders and fees every week.

Practical checklist

• Map your payment flow and find out which acquiring bank actually sits behind your provider.
• Offer the methods your customers expect: local and international cards, a mobile wallet, and cash on delivery if your market needs it.
• Enable 3-D Secure and track its failure rate.
• Know your settlement cycle and reserve, and reconcile payouts weekly.
• Publish a clear refund policy and make your billing descriptor recognizable.
• Review decline rate, chargeback rate and payment cost per order alongside your other e-commerce KPIs.