Payment Processor: What It Is, How It Works, and Top Providers (2025)

Have you ever paused to think about what happens behind the scenes when your customer swipes a card, initiates a UPI transfer, or sends you money from abroad? How does that payment move between banks, networks, and borders before it reaches your account?

The simple answer to that question is: payment processors. They are the infrastructure that sends every electronic payment from the customer's account to your bank while also protecting sensitive data and making sure settlements happen on time. 

In this blog, we demystify payment processors, how they work and also introduce you to the best payment processor providers in 2025. 

• A payment processor is a system that sends payments from your customer's bank account to yours through secure channels. Most payment processors work with multiple payment methods, and some support cross-border payments. 

• Payment processors kick into action when a customer initiates a payment. The processor then encrypts the information, gets it authorized by the issuing bank, shares it with the acquiring bank, informs you that the payment has been authorized and finally settles the payment. 

• The right payment processor allows you to accept multiple payment methods and payments in multiple currencies while you receive them in your account in INR. Xflow is one of the leading cross-border payment processors in the market. 

A payment processor is a platform that directs electronic payments from your customers to you. When a customer pays you for your product or service using their card, like Visa/Mastercard/Amex, or any other digital payment method, the payment process securely takes that money from their account and deposits it into your business account. 

On the surface, payment processors move money from the issuing bank (customer's account) to the acquiring bank (business's account). Their functions are, however, slightly more nuanced than that. 

Here's what a payment processor does: 

1. It receives and transmits payment information between your bank and your customer's bank.

2. Prompts the bank to check if there are enough funds in the customer's account, if the payment method is valid, and if all the details provided are legitimate. It also uses encryption to secure sensitive payment data. 

3. Ensures that funds are credited to the merchant's account after the transaction has been processed. 

4. Many processes help businesses with global expansion by offering multiple currency support and local payment methods.

Here's how the payment processor sends transactions from a customer's account to a business's account. 

1. Payment initiation 

The process starts with a customer initiating a payment by providing their information. This could be a card number or wallet details. This can happen in person through a POS terminal or online through an e-commerce website, a payment link or app. 

2. Data encryption 

The moment a customer's data is received, it needs to be encrypted and tokenized to prevent data theft. The processor takes care of this process. 

3. Data transmission 

Post-encryption, the processor transmits the data and forwards the information to the acquiring (business's) bank, which then transmits it to the issuing (customer's) bank through the appropriate method.

4. Request authorization and response 

At this stage, the customer's bank checks that they have enough funds available and the authenticity of the payment method used. It then sends an authorization code to the business's bank. If the customer's bank finds an issue with the transaction request, it sends back a decline code. 

The payment processor receives this authorization or decline confirmation and forwards it to the business. 

5. Payment completion 

Once the authorization process has been completed, your business delivers the product or service to the customer, and the payment is complete.

6. Capture and settlement 

Finally, the payment is "captured" or sent from the customer to the merchant's account. From the merchant account it is settled into your business account. This transfer usually takes 1-3 days after the payment is made. 

The way a payment processor works both offline and online is quite similar in terms of how the transaction flow moves, starting with payment initiation, moving on to encryption and authorization and finally ending with settlement. 

However, there are some differences. In an offline transaction, the payment is initiated through a point-of-sale terminal, whereas online, it is initiated through your website, payment link or app. Here's how they differ: 

Payment methods can usually be classified based on how they manage merchant accounts and what geographies they service. Here are some common types of payment processors: 

Based on how merchant accounts are set up: Aggregators vs Dedicated Accounts 

1. Aggregators

If a payment processor is an aggregator, it means multiple businesses are pooled together under one large merchant account that the processor owns. In this case, you can start accepting payments almost instantly, as you do not have to wait for a new account to be set up. 

2. Dedicated merchant accounts 

In this model, every business gets its own merchant account linked to its bank account. This can take a bit longer to set up as it requires documentation and authorization. 

Based on geography and currency support: Domestic vs Cross-Border 

1. Domestic processors 

They handle transactions within one country and are usually optimized to handle local payment methods. For example, a domestic payment processor in India would integrate UPI payments, whereas one that is US-based would offer ACH transfers. 

2. Cross-border processors

Cross-border payment processors can handle payments across country borders. They also manage currency conversion and FX rates. Some processors like Xflow can help you meet cross-border payment compliance requirements automatically. 

If you have been looking up payment processors, the terms payment gateways and merchant accounts may have also come up quite frequently. Now, on the surface, these three terms may seem like the same thing, but they are not actually interchangeable.

To understand them better, let's start by defining them: 

A payment processor is the system that moves payment data between the customer's issuing bank, the card network (Visa, Mastercard, Amex) or any other payment rail, and the merchant's acquiring bank.

A payment gateway is the customer-facing technology layer that securely captures customer payment details online or at a POS and sends them to the processor for authorization.

A merchant account is a unique bank account where funds from a transaction are first deposited before moving into the business's operating bank account.

Here's a side-by-side comparison: 

A lot of payment processor providers today also provide payment gateways, so businesses don't need to source them separately. Similarly, payment processors often give businesses access to merchant accounts without requiring them to open one directly with a bank. 

Before payment processors were created, businesses had to depend on cash transactions, paper checks or bank transfers through processes like ACH, wire transfers, NEFT and RTGS. These processes were slow and inconvenient. So, here's how payment processors have made transactions easier: 

1. Accept multiple payment methods 

Customers usually prefer paying through payment methods that they are familiar with. A payment processor can support multiple payment methods, such as global card networks like Visa, Mastercard and Amex and also local payment rails like UPI in India and ACH in the US. 

Offering payment methods that customers like improves their satisfaction levels and lowers the chances of them abandoning their carts. 

2. Fast and reliable settlements 

Payment processors route your payments through reliable and secure channels. They handle security measures like encryption and compliance with regulations while still giving you faster settlement cycles. 

Faster settlements can improve your cash flow, and reliable settlements reduce the risk of disputes with your clients or banks. 

3. Security and compliance 

Payment processors are required to comply with security standards and processes, including PCI DSS, tokenization requirements, KYC and AML processes. This means you can automatically benefit from secure, compliant transactions without having to worry about building independent systems for compliance. 

4. Global reach 

Lastly, since a lot of payment processors support multiple currencies and payment methods, they make payments easier for your international customers. Your customers can choose to pay using their preferred payment methods and local currency and can you get settled in INR.

Here are some things to look for when selecting a payment processor for your business: 

1. Payment method coverage

Check if the payment processor supports all the payment methods your customers are likely to use. Broader coverage improves the number of successful transactions and increases customer satisfaction. 

2. Multi-currency and cross-border payments

If you service international customers, your processor should allow billing in multiple currencies. It should also offer FX conversion capabilities and settlements in your local currency. Without checking for this, you may be stuck with a processor that charges high FX fees and faces issues when collecting global payments.  

3. Settlement speed and fees 

Faster payment cycles and transparent fees give you predictable cash flows for smoother operations. So, find out what the settlement cycle of the processor looks like: is it T+1, T+2 or longer? 

Also, consider the associated costs, including the transaction fees, FX markup, chargeback fees and hidden charges if any. 

4. Security and fraud protection 

Pick a processor that actively protects sensitive data with PCI DSS compliance, tokenization, encryption and fraud monitoring systems. This helps you reduce chargebacks and maintain customer trust. 

5. Compliance support 

Lastly, the processor must comply with all local and international regulations. This includes FEMA and RBI compliance in India and PCI DSS, GDPR, and AML/KYC regulations globally. 

Now that you know what to look for in a payment processor, here are some of the best payment processors in 2025: 

1. Xflow

Xflow helps Indian businesses receive payments from international clients. It offers low FX costs, RBI/FEMA compliance, and audit-ready documentation like FIRC/FIRA. It supports multiple currencies and payment methods with limitless transactions, transparent fees and quick settlement. 

2. Stripe

Stripe offers powerful APIs and supports multiple payment methods and currencies. However, its fee structure can be on the higher end. 

3. PayPal

Paypal is a widely recognised payment processor that offers cross-border payments and instant account setup. Its downside is the high FX markup and hidden transaction fees. 

4. Razorpay

Razorpay is a leading Indian payment processing platform. It offers multiple payment methods and some international payment support. However, its cross-border payment processing capabilities are not as advanced as some of the other payment processors we've covered here. 

5. Square

Square started as POS hardware and has grown to become a payment processor that handles offline and online payments. It is heavily focused on North America and has limited availability in other markets. 

Some other popular payment processors include Ayden, Authorize.Net and Braintree. These are also well-established global platforms that offer multi-currency transactions.

Here are some challenges that may come up if you're looking for the right payment processor. 

1. Hidden fees and complex pricing: Platforms may advertise a flat fee but charge extra for FX conversions, chargebacks and delays. Compare fee structures before making your choice. 

2. Compliance and regulatory requirements: Keep in mind that not all processors handle compliance equally or adequately, and the wrong one can put your business at risk. Check for compliance with FEMA, RBI guidelines, data localization, tax rules, PCI DSS, GDPR and AML/KYC. 

3. Market coverage: Not all platforms support every rail or currency. The more geographies, currencies and payment methods a processor covers, the better chances you have at targeting a global clientele. So, find a processor that offers wide support. 

4. Integration complexity: Some processors may require lengthy and complex onboarding and integration. Find processors like Xflow that offer easy APIs and SDKs for quick setup. 

When choosing a payment processor, you need to ensure that it is one that complies with all local and global requirements and also has a strong security framework. 

In India, processors need to comply with: 

1. Foreign Exchange Management Act (FEMA), 1999, by assigning the right purpose code to each transaction and maintaining extensive documentation. 

2. RBI guidelines for payment aggregators and payment gateways, which say that only RBI-approved aggregators can collect payments, and a merchant's KYC must be maintained.

3. Payment and Settlement Systems Act, 2007 (PSS Act), which is a legal framework for payment systems. 

4. Prevention of Money Laundering Act (PMLA), 2002, which requires KYC for all customers and the reporting of any suspicious transactions to the Financial Intelligence Unit (FIU-IND).

5. Income Tax Act, 1961 and its regulations regarding transfer pricing and reporting. It also requires FIRC/FIRA filing for every foreign payment. 

6. The RBI localization circular, according to which all payment data of Indian users must be served on processors in India, and for payment processed abroad, copies should be deleted within 24 hours, and the primary data must remain in India. 

Globally, processors have to consider: 

1. The PCI DSS (Payment Card Industry Data Security Standard) is a mandatory regulation for any business that handles cardholder data. 

2. Privacy regulations such as PSD2 and GDPR. 

3. Anti-Money Laundering and Counter-Financing of Terrorism laws that apply in most countries. 

Lastly, payment processors must also follow security regulations and best practices. These include encryption and tokenisation of sensitive information, using 3D secure for authentication, and active fraud monitoring and reporting. 

Thinking about integrating a payment processor into your existing business platform? Here are some things to keep in mind: 

1. Use a processor that offers APIs so that you can integrate it directly into your platform and help customers complete payments without getting redirected to another platform. Processors like Xflow offer whitelabeling capabilities so you can create fully branded payment experiences while the processor works in the background. 

2. Build a sandbox environment to test how the processor works before actually rolling it out. Try success, decline, partial captures and other scenarios. Also, try multi-currency payment cases. 

3. Lastly, set up a failover mechanism so that your payments don't stop if one method has an issue. Set up as many payment rails in the processor as possible and mechanisms to route transactions to an alternate method in case payments fail. 

Traditionally, cross-border payment transactions can be slow and expensive. However, Xflow simplifies this entire process and gives you a payment stack that is fast and transparent. 

Here's what you get with Xflow: 

1. Faster settlements

Xflow offers T+1 day INR payouts, which means you can receive payments from global clients in your Indian bank account quickly. 

2. Local collection experience for global clients

Xflow receiving accounts allow your clients to pay through local currency transfers instead of expensive wire transfers. These accounts support 30+ currencies, so you can accept payments globally while clients enjoy convenience similar to making a domestic transaction. 

3. Transparent FX conversion and limitless transactions

A major concern with cross-border transfers is the huge FX rates. Xflow offers fixed 0.3%-0.5% FX markups and helps you save up to 50% of FX. It also removes all transaction limit restrictions, which means you can process large invoices without having to break them up into multiple smaller transactions. 

4. Built-In compliance and documentation

In India, every cross-border transaction must comply with RBI guidelines. Based on that, you have to file FIRA or e-FIRC documentation against every international transaction. Xflow automates FIRA filing and keeps your business compliant with RBI requirements. 

Xflow makes your workflow smoother by integrating with your accounting and CRM tools. It connects via APIs with your accounting tools and CRM platforms. This system brings all your invoices, payment instructions, and balances to a single platform. When you connect it with your CRM tool, you can send automated invoices and reminders to your customers. 

Xflow also makes your customers' interactions with your brand seamless by designing branded checkout experiences. Xflow's API lets you embed cross-border payment options right into your platform with your own branding, so that customers do not have to be redirected to another platform for payments. 

As a business looking to expand into the global marketplace, you need to offer your customers an easy and quick way to pay you. The best way to do this is by finding a payment processor that allows your customers to pay in their local currency through local payment methods that they are familiar with. At the same time, you need to be able to receive these payments in India, quickly and without losing a huge chunk of it to FX conversion markups or processing fees. 

If there is one payment aggregator that can check all of these boxes for you, it would be Xflow. 

Xflow is a B2B payment platform designed specifically for businesses that receive payments from abroad. It gives you virtual receiving accounts, fast (T+1) settlement timelines, transparent FX rates and no transaction limits. Additionally, the platform keeps you fully compliant with RBI regulations by auto-issuing FIRA/eFIRC documents just within 24 hours of a transaction. 

Want a payment processor that integrates fully with your platform using APIs and offers 100% secure payments with ISO 27001 and SOC 2 compliance? Sign up for free with Xflow today!