Payment Rails: ACH, SWIFT, RTP & Other B2B Payment Networks Explained

The ACH Network, regulated by Nacha, processed an astounding $93 trillion in payment value in 2025, making it one of the most popular online payment rails worldwide. This transaction category includes automatic bill payments, brokerage account deposits, and direct payroll deposits.

ACH transactions tend to take two to three days, although Same Day ACH and Next Day ACH are available (if specified business-day time windows are met). The Automated Clearing House network handles both debit and credit ACH transactions.

ACH fees cost between $0.20 and $1.50 per transaction, depending on your location, the financial institutions used, whether you’re making international or domestic ACH payments, and other factors.

How ACH Works

A bank must act as the Originating Depository Financial Institution (ODFI) for all ACH transactions, which are their customers’ bank transfers. The bank sends these details to the central clearinghouse in the ACH Network.

The responsibility for verifying the existence of the bank account and the availability of sufficient funds to complete the transfer lies with the individual or company transferring the funds.

Credit cards are another popular payment rails platform. They run on an independent network operated by companies that provide the technology to power their transactions. Visa, Mastercard, American Express, and Discover are major credit card companies in the United States. Visa processed 257.5 billion transactions worldwide during its fiscal year 2025, which ended September 30th. Mastercard processed 210.3 billion transactions globally in calendar year 2025.

These card networks charge merchants fees (1.5 to 3.5% plus $.20 to $.30 flat fee per transaction) to process payments using their payment infrastructures. The bank or company that sponsors the customer’s card is called the issuing bank or sponsor bank. In comparison, an acquiring bank is a financial institution that processes credit or debit card payments on behalf of a merchant.

As real-time payments are experiencing increased demand worldwide, card networks are also evolving to support new payment technology that allows faster payment settlement. Push-to-card is one way companies leverage the existing card networks. For example, Lyft and Uber have introduced push-to-card solutions (Lyft Direct and Uber Instant Pay) that allow drivers to instantly receive their earnings to their debit cards.

According to SOFI, in December 2025, the average card processing fee ranged from 1.5 percent to 3.5 percent per transaction.

How Card Rails Work

In card transactions, the transactions flow through the card network, from the merchant’s acquirer or payment processor to the consumer’s issuing bank in real time.

PayPal is a global payments company that facilitates online payments between parties. PayPal is responsible for a large share of global payments today, processing 25.4 billion transactions in 2025. Founded in 1998, PayPal is an established global network, though it also owns Venmo, a mobile payment rail that operates only in the United States.

PayPal allows customers to register an account using an email address linked to their card or bank account. When identification and proof of funds are confirmed, users can begin sending or receiving payments to and from other PayPal accounts online or through the company’s app.

PayPal’s transaction payment processing rates range from 2.99% to 3.49% of the transaction amount (or 4.99% for PayPal Pay Later options), plus a fixed cost of 49 cents for domestic transactions and varying rates for international transactions.

How PayPal Works

PayPal verifies all the user information to ensure the person setting up the account is the rightful owner before the customer can use the service. PayPal serves as a wallet. PayPal enables user-to-user transfers, linking to each user’s bank account or credit/debit cards, and ACH transactions.

Real-Time Payments (RTP) is a payment processing network that enables instant, electronic transfers of funds between banks in the United States. Payments by RTP (and its competitor, FedNow) are not reversible. The Clearing House RTP Network was launched in November 2017 to provide real-time payments serving retail and commercial customers.

Financial institutions that hold 90% of U.S. demand deposit accounts (DDAs) can use the RTP network’s real-time payment capabilities, and the network already reaches 71 percent of U.S. DDAs. In addition, financial institutions can directly connect to the RTP network, or connect indirectly through Third-Party Service Providers, including Bankers’ Banks and Corporate Credit Unions.

RTP Network pricing is low, depending on the type of transaction or service used. Clearing House RTP pricing in 2026 for network transactions is $0.01 per Request for Payment (RfP) Sent or Remittance Advice Sent and $0.045 per payment for each Inter-Participant Credit Transfer Sent. Additionally, the RTP has a $.10 Request for Payment (RfP) Incentive Fee, payable to the Other Participant initiating the RTP Credit Transfer rather than to the RTP network. 

How RTP Works

The Clearing House is responsible for processing all RTP payments. RTP is based on a liquidity model in which member financial institutions are required to maintain a minimum account balance with the Federal Reserve to ensure immediate funds transfers.

For example, when you pay your utility bill for the month using RTP.

1. Your bank sends a message to the network that includes the payment details.
2. The Clearing House checks the liquidity of your bank.
3. The Clearing House processes the message and routes it to the utility company’s bank account.
4. RTP uses the ISO-20022 standard for the messages used to initiate payments and retrieve transaction status.

RTP transactions happen instantaneously. The RTP network will immediately decrease the sender’s financial institution’s balance and boost the receiver’s financial institution’s balance once a transaction has been completed.

A blockchain is an auditable, distributed database that’s shared across several computers linked together in a peer-to-peer network. Blockchains maintain a secure, decentralized record of transactions in cryptocurrency systems such as Bitcoin and Ethereum.

Cryptocurrencies are the digital currencies exchanged on the blockchain network, and they’re growing in popularity as payment rails. For example, the annual volume of cryptocurrency payment transactions grew to $46 trillion as of October 2025, up 106% from the previous year, according to Yahoo Finance, citing Andreessen Horowitz’s State of Crypto 2025 report.

Blockchains allow digital information to be recorded and distributed but not edited. It guarantees the integrity and security of data records and builds trust without the need for a trusted third party.

Fees for exchanging cryptocurrency on the blockchain vary depending on the exchange being used.

How Blockchain Works

While there are many cryptocurrencies, most are based on the same blockchain technology. While Bitcoin and many other cryptocurrencies use the traditional mining (Proof of Work-PoW) technique, Ethereum has switched from mining to a staked approach (Proof of Stake -PoS) for its transaction validation method. 

Mining involves steps to verify the validity of a cryptocurrency transaction and record it in the blockchain.  Each cryptocurrency blockchain has its own set of “mining rules.”

SWIFT is a global financial messaging network used to send standardized payment instructions between financial institutions. SWIFT is not a payment rail. SWIFT payments go through selected payment rails specified in the message payment instructions.

In 2026, more than 11,500 global SWIFT member institutions sent an average of 53.3 million FIN messages per day across 224 countries and territories in its network. 

As an estimate, you can expect the big banks to charge exchange rate costs on a transfer using SWIFT messaging. SWIFT charges low messaging fees per transaction and Request for Payment (RfP). The amount varies with the amount you send and the number of banks involved in the transaction.

How SWIFT Works

Although SWIFT has become a significant part of the global financial infrastructure, it’s not a financial institution. Instead, SWIFT is a messaging network that operates as a carrier of payment instructions between financial institutions participating in a transaction. It communicates transaction orders between these institutions using SWIFT codes, which it administers as the registrar of codes established by ISO 9362. A SWIFT code is also known as a BIC code (Business Identifier Code).

SWIFT assigns every financial organization a unique code with 8 or 11 characters. For example, let’s assume a transaction involving a Citibank account in New York to a Deutsche Bank branch in Berlin.

1. The New York customer can walk into their Citibank branch with the receiver’s account number and Deutsche Bank’s unique SWIFT code for its Berlin branch.
2. Citibank will send a payment transfer SWIFT message to the Deutsche Bank’s branch over the secure SWIFT network. When Deutsche Bank receives the SWIFT message about the incoming payment, it will clear and credit the money to the receiver’s account in Berlin.

The single euro payments area (SEPA) is a framework for cashless payments that harmonizes how payments are processed across euro countries. SEPA is a popular payment rail across Europe, facilitating over 50 billion euro transactions per year in 41 member countries (including some countries not part of the euro area or EU).

The SEPA initiative aims to make cross-border electronic payments as inexpensive and easy as payments within one country. European consumers, government agents, and businesses that make payments by direct debit, instant card transfer, and credit transfers use the SEPA architecture.

Transaction fees for a SEPA transfer are the same as for domestic payments.

How SEPA Works

SEPA bank transfers come in three types, each with its own use case. To begin, all SEPA transfers employ the IBAN (International Bank Account Number) and, in some cases, the BIC (Business Identifier Code) numbers of both the sender and recipient’s bank accounts to transfer funds.

1. SEPA Credit Transfer — This allows for fund transfer between banks, typically within one business day.
2. SEPA Instant Credit Transfer (also referred to as SEPA Instant Payment) allows for near real-time fund transfers (less than 10 seconds). Once the Payment Service Provider recognizes that the SEPA transaction is an instant payment, it processes and clears the amount immediately, rather than in batches as with a regular credit transfer.
3. SEPA Direct Debit Transfer — This allows for recurring payments such as monthly rent, internet, or electricity bills, or regular loan repayment installments. Before the transaction can occur, the sender must sign a “mandate,” a contract that allows the recipient of the funds to repeatedly withdraw money from the sender’s account.

The recipient of the funds requests that the sender’s bank withdraw the recurring amount. The sender’s bank validates the pull request and the mandate and settles the transaction. The entire payment process is handled by the sender’s and recipient’s banks.

SEPA Core Direct Debit Transfer is available to individuals, and the SEPA B2B Direct Debit Transfer is available between businesses.