Ecommerce Payment Processing: How It Works, What It Costs, and How to Choose

What Is Ecommerce Payment Processing? 

Ecommerce payment processing is the digital system that lets online stores accept, authorize and settle online payments from customers. U.S. ecommerce sales increased 12.2% from Q2 2025 to Q2 2026, accounting for  17.1% of total retail sales in Q2 2026. 

To reach today’s shoppers, ecommerce retailers need to support the online payment methods customers prefer: cards, digital wallets and, increasingly, account-to-account payments. Here’s what you need to know about ecommerce payment processing, the key players and fees involved, and how to choose the ecommerce payment solution. 

The Core Components of Ecommerce Payment Processing 

There are several key components of ecommerce payment processing:

Payment gateway: A software application that captures and encrypts customer payment data at checkout and transmits it to the payment processor. 

Payment processor: A company or service that facilitates electronic transactions (such as debit/credit card or digital wallet payments) between customers and businesses. The payment processor 

• Securely routes transaction details through the card network to the issuing bank (the customer’s bank) and the acquiring bank (the merchant’s bank)

• Requests authorization (i.e., checks the availability of sufficient funds or credit) 

• Verifies the customer’s identity and payment method, helping prevent fraud and unauthorized transactions

• Coordinates the transfer of funds from the issuing bank to the acquiring bank (the merchant account). 

Merchant account: a specialized bank account that lets an online business accept and temporarily hold electronic payments before they transfer to the company’s main business bank account. Merchant service providers provide online businesses with merchant accounts, payment gateways and payment processing for ecommerce and other businesses.  

How Ecommerce Payment Processing Works 

Payment information moves quickly through several steps: 

1. Data entry and encryption. 

Ecommerce payment processing starts when a shopper inputs their payment details on the merchant’s checkout page. The payment gateway captures the sensitive information, encrypts it and securely routes it to the payment processor. 

2. Authorization and verification.

The payment processor receives the encrypted request and forwards it to the appropriate card network (like Visa, Mastercard, Discover or American Express).The card network communicates with the customer's card-issuing bank, which checks for active status, sufficient funds or credit limit, and fraud risk. 

3. Payment approval or decline. 

If there are sufficient funds or credit, the card-issuing bank approves the transaction. If not—or if the bank suspects fraud—the bank declines the transaction. The issuing bank sends an approval or denial code back through the card network, the processor, and the payment gateway to the merchant's website. This all happens in roughly 2 – 3 seconds. Once the payment has been approved, the online store confirms the customer’s order and sends a confirmation message to the customer. If the payment is declined, the customer receives an error message and is asked to try again or seek help.

4. Settlement. 

The issuing bank transfers the net funds (minus interchange fees and processor fees) through the card network to the merchant's bank account. Funds typically re the merchant account within 1 – 3 business days. 

Ecommerce Payment Methods

Ecommerce payments take place over the internet, but the payment methods vary considerably. Several ecommerce payment methods exist, and the available options are evolving. To meet customer preferences and facilitate the payment process, consider accepting as many ecommerce payment methods as possible:

Credit cards: Credit cards have 16-digit numbers (except American Express cards, which have 15 digits) plus an expiration date and security code. When a customer pays with a credit card, the sale amount is deducted from their credit line. If the customer has enough remaining on their credit line, the issuing bank typically authorizes the transaction. 

Debit cards: Debit cards have 16-digit account numbers, an expiration date and a security code. They’re connected to a customer’s bank account, typically a checking account. When a customer pays with a debit card, the funds are pulled from their bank account.

Prepaid cards: Prepaid cards work like debit cards but aren’t connected to a bank account. Instead, someone purchases a card and “loads” a certain amount of money onto it. Every time they use the card, the purchase amount gets deducted from the available amount. Some prepaid cards are reloadable, while others—like gift cards—are not. If there aren’t enough funds on the card, the transaction gets declined. 

Digital Wallets: Digital wallets such as Apple Pay or Google Pay store customers’ credit or debit card information. Digital wallets can be used on any device, including a smartphone, tablet or laptop. Encryption, tokenization and biometric security make digital wallets one of the safest payment methods. By providing easy, one-tap checkout, digital wallets boost mobile conversion. 

Online payment services: Online payment systems like PayPal and Amazon Pay connect to a customer’s bank account or credit/debit card. Shoppers log in to the payment platform at online checkout instead of entering their payment details. 

Bank transfers: A bank transfer— often handled by Automated Clearing House (ACH) in the U.S.—pulls money directly from a customer’s bank account (usually a checking or savings account). To perform the transfer, the customer needs to provide their account number and bank’s routing number. Single Euro Payments Area (SEPA) Direct Debit is the European Union equivalent of ACH. 

Echecks: eChecks are often confused with ACH payments, but the two methods differ. eCheck is a form of ACH, but it’s not ACH itself. When paying by eCheck, the customer provides information that would be found on a paper check and authorizes the payment. Echecks take longer to clear and settle (3 – 5 days) than ACH payments (1 – 3 days). 

Buy now, pay later (BNPL): Customers split the cost of purchases into installments. BNPL programs are typically offered through a third party, which collects customer payments and may charge interest. BNPL programs reduce purchase hesitation on higher-priced items, boosting average order value. Klarna, Afterpay and Affirm are popular BNPL providers. 

Cash on delivery (COD): COD is an old-school payment method that’s still popular in some parts of the world, where many shoppers are unbanked, lack credit cards, or prefer not to share financial details online. With COD, a customer orders a product or service and pays in cash when the item arrives or the service is performed. 

Here’s a side-by-side comparison of the most widely used ecommerce payment methods:

Ecommerce Payment Processing Fees

Ecommerce payment processing fees vary by payment method and provider. Understanding how ACH and card-processing costs are structured can help you compare options and manage expenses.

ACH Processing Fees

ACH transaction fees are typically lower than fees for credit card processing for e-commerce. The ACH fee structure may be:

• Flat rate (typically $0.20 - $1.50 per transaction) 

• Percentage-based (typically 0.5% - 1.5% of the transaction, often capped at $5.00)

Credit/Debit Card Processing Fees

There are three main types of credit and debit card processing fees:

• Interchange fees. Paid to the cardholder’s issuing bank, these fees are a combination of a percentage of the transaction value and a fixed per-transaction fee. Interchange fees vary based on the type of card (credit, debit, rewards, corporate, etc.), the type of transaction (swiped, dipped, tapped, keyed or online) and the business’s industry.

• Assessment or network fees. Set by and paid to the card networks—Visa, Mastercard, Discover and American Express in the U.S.—these fees cover the cost of operating and maintaining the card-network infrastructure. Assessment fees are usually a small percentage of the transaction value and may vary slightly between card networks.

• Processor or merchant services fees. The payment processor or merchant services provider charges a fee—a fixed per-transaction fee, a percentage of the transaction value, or a combination—for their role in facilitating credit card transactions. 

All those fees add up quickly. Standard, flat-rate credit card processing fees are usually 2.9% - 3.5% of the transaction value, plus $0.30 per transaction. Debit card transactions usually have lower processing fees (0.5% - 1.5%) than credit card transactions because debit cards have lower interchange rates. 

Credit/Debit Card Processing Fee Structures 

Credit/debit card processing fee structures usually fall into one of three categories: flat rate, interchange-plus, or tiered pricing. Here’s how they compare:

Charges for credit card processing for ecommerce may include hidden fees such as:

• Monthly payment gateway fees. Merchants pay a recurring monthly fee for the secure authorization, encryption, and transmission of  online credit card or digital transactions.

• Chargeback fees. Merchants pay a non-refundable penalty when a customer disputes a transaction directly with their bank.

• PCI compliance fees. Payment processors charge an annual or monthly fee to administer, support and monitor a business’s security program. The fee covers administrative costs, access to a compliance portal, Self-Assessment Questionnaire (SAQ) tools, or vulnerability scans.  

Security, Fraud Prevention and PCI Compliance 

The Payment Card Industry Data Security Standard (PCI DSS) mandates that all businesses that handle, process, transmit or store card data follow 12 core security requirements, including protecting stored account data and encrypting cardholder data. 

To protect payment data and meet PCI compliance obligations, ecommerce payment processing should incorporate these security/fraud prevention measures:

3D Secure 2.0. 3D Secure (3DS) is a security protocol that adds an authentication step to certain online card payments. 3DS may be required under Europe’s Strong Customer Authentication rules or triggered by merchant criteria, such as a transaction over $500 or one made from an unfamiliar device. When prompted, the customer typically approves the purchase through their bank’s website or app using a one-time password or biometric information. Visa Secure and Mastercard Identity Check are the card networks’ implementation of a 3DS 2.0 authentication protocol. 

Address verification system (AVS). AVS is a credit card fraud-prevention tool used during card-not-present (CNP) transactions—such as online orders—to confirm that the billing address entered by a customer matches the address on file with the card’s issuing bank. 

CVV (card security code) checks. A card verification value (CVV) check is a security measure used during online (card-not-present) transactions. The check confirms that the person making the purchase physically has the credit card by matching the 3- or 4-digit CVV code provided at checkout with the issuing bank’s records. 

Tokenization. Tokenization turns sensitive credit card and other payment data into randomly generated tokens. On their own, the tokens have no value, so they can’t be used elsewhere if they’re intercepted by a fraudster. 

Hosted payment pages. Storing sensitive payment data puts your business and customer at risk for fraud. Using a hosted payment page means that your business doesn’t store payment details on its servers. Payment information is stored securely and your PCI DSS scope is reduced. 

End-to-end encryption. Encryption transforms data into strings of gibberish, making it useless if intercepted. Payment Card Industry-validated, end-to-end encryption meets PCI DSS requirements. 

What to Look for in Ecommerce Payment Solutions 

How do you choose from the various ecommerce payment solutions? You need an ecommerce payment processing system that meets your business’ unique needs. Look for these features and capabilities when choosing your payment solution: 

1. Robust security measures. Choose a payment solution that provides the security and fraud prevention tools described in the previous section.

2. Ability to accept several payment methods. The more payment methods you offer, the wider your customer base. Choose a payment solution that lets you accept credit and debit cards, ACH payments and digital wallets. 

3. Transparent fee structure. Payment processor fees vary. Before choosing an ecommerce payment processor, review its fees, including setup and monthly subscription fees as well as transaction fees. Read the fine print so you’re not surprised by hidden costs. 

4. Ability to process international payments. When you sell online, you may have customers all over the world. To accommodate customers from other countries, choose a payment solution that accepts and processes multiples currencies. 

5. Scalability. Your ecommerce payment solution should be able to handle traffic spikes (such as during holidays or flash sales) and higher transaction volumes as your business grows. Choose a payment solution that can accommodate new sales and payment channels to meet evolving business needs and consumer preferences. 

6. Ease of integration. Choose a payment solution that connects easily to your:

• Ecommerce platform (such as Shopify, WooCommerce, Magento, or BigCommerce)

• Accounting system

• Enterprise Resource Planning (ERP) and inventory management systems

• Subscription billing platforms 

• Other existing systems

Consider the Technical requirements and ease of setup. Will integration require significant development work and coding expertise, or are there pre-built integrations? 

Why Partner With CSG Forte for eCommerce Payment Processing? 

If you sell online, you need an ecommerce payment solution that’s flexible, secure and affordable. CSG Forte is a complete payment solution that lets you accept credit/debit cards, ACH payments and digital wallets, plus:

• Supports omnichannel payments, allowing you to take payments in person and over the phone [via Interactive Voice Response (IVR)] as well as online. 

• Protects payment data and reduces ACH and credit card fraud through tokenization, encryption, ACH payment validation, hosted payment pages and built-in PCI DSS compliance. 

• Offers several pricing structures, so you can choose the option that best fits your transaction volume. 

Contact us today to learn more about CSG Forte or sign up for an account. 

Ecommerce Payment Processing FAQs 

How do I add payment processing to my ecommerce site?

Gather business identity/verification documents (e.g., business tax ID number, business registration documents, business bank account details), required by payment processors. Set up a merchant account or select a payment service provider. Select a payment gateway (many PSPs include a built-in gateway). Connect your payment processing system to your ecommerce platform. Most major platforms like Shopify, WooCommerce, and BigCommerce offer built-in integrations to simplify setup.

How do you optimize payment processing for ecommerce?

Optimization focuses on three levers: improving authorization rates (reducing false declines on legitimate transactions), recovering failed payments automatically (using tools like account updaters and automated retry logic), and streamlining checkout (fewer steps, guest checkout, mobile-friendly digital wallet options). Gateway orchestration—routing payments across multiple processors—also improves resilience and approval rates.

How do you use payment processing for B2B ecommerce sites?

B2B ecommerce payments typically involve higher transaction values, net payment terms, and invoicing rather than immediate card payments. ACH/bank transfers are the preferred B2B method because their flat or low-percentage fees are far more cost-effective than card rates for large orders. B2B processors should support approval workflows, purchase order matching, and recurring billing for ongoing vendor relationships.

How do you handle taxes on payment processing for ecommerce?

Payment processing and tax remittance are separate responsibilities. The processor moves money and captures transaction data (amounts, timestamps, customer location); the merchant is responsible for calculating and remitting sales tax or VAT based on applicable laws. The transaction records your processor provides are essential for reconciliation and accurate tax reporting, so make sure your processor’s reporting tools export the data your accounting or tax software needs.

How long does ecommerce payment processing take?

Authorization happens in roughly two to three seconds, so the customer sees an immediate approval or decline. Settlement—the movement of funds into your merchant account—typically takes one to three business days, though some providers offer next-day or same-day funding for a fee.