Online payment fraud detection: best strategies and prevention tips

Key takeaways

• Online payment fraud detection uses tools like machine learning, 3D Secure (3DS), and tokenisation to spot and stop fraudulent transactions before they cost you money.

• Common fraud types like chargeback fraud, card-not-present (CNP) fraud, and account takeovers are getting more sophisticated, so staying ahead means using layered prevention strategies.

• Airwallex's ML-powered fraud detection engine analyses transactions in real time and supports adaptive 3DS, helping you reduce chargebacks and protect revenue across 180+ countries.

According to JP Morgan research, 71% of businesses have experienced payment fraud attacks.¹ As digital transactions keep growing, the methods fraudsters use to exploit them are growing too. From AI-driven detection to biometric verification, businesses are investing more than ever in tools that can keep up with new fraud tactics.

This guide breaks down the most common types of online payment fraud, the technologies that detect them, and practical strategies you can use to protect your business and your customers.

What is online payment fraud detection?

Online payment fraud detection is the process of identifying and blocking fraudulent transactions before they go through. Think of it like a security camera that doesn't just record. It watches every transaction in real time and flags anything that looks off.

Modern fraud detection combines rule-based checks, like blocking transactions from high-risk countries, with machine learning models that learn from your transaction history. These models analyse patterns across thousands of data points, including purchase amounts, device types, locations, and time of day, and assign a risk score to each transaction. When a score crosses a certain threshold, the system can block the transaction, ask for additional verification, or flag it for manual review.

The practical benefit is simple. You catch fraud faster, reduce chargebacks, and avoid the operational headache of investigating suspicious activity after the fact. And because these models learn from every transaction, they get more accurate over time.

So, why does all this matter for your business? Let's look at what's at stake.

How online payment fraud affects your business

A single fraudulent transaction doesn't just cost you the sale. You'll also face chargeback fees, spend hours on investigations, and risk losing the customer's trust for good. The impact spreads across three areas:

• Financial losses. Direct theft, chargeback fees, and the cost of replacing goods or services add up quickly. For high-volume merchants, even a small uptick in fraud rates can eat into margins.

• Reputational damage. Customers who experience fraud on your platform may not come back, and they'll tell others. Negative reviews and social media complaints can put off new customers before they even get to your checkout.

• Operational burden. Investigating fraud, managing disputes, and reinforcing security measures all take time and resources. Your team ends up firefighting instead of focusing on growth.

Understanding the specific types of fraud you're up against is the first step in building your defences.

Common types of online payment fraud

Chargeback fraud

Chargeback fraud, sometimes called friendly fraud, happens when a customer makes a legitimate online purchase but later disputes the charge with their bank, saying they didn't receive the item or didn't authorise the purchase. The bank reverses the charge and refunds the customer, even though the transaction was valid. That leaves your business paying for the lost revenue, the product, and a chargeback fee on top.

With friendly fraud accounting for over 70% of all chargebacks,² strong fraud detection and chargeback insurance can save your business thousands in lost revenue and fees.

How you can prevent chargeback fraud:

• Draft clear policies regarding returns, refunds, and shipping to avoid customer misunderstandings

• Implement package tracking and collect proof of delivery (POD)

• Communicate with customers promptly

• Use a payment processor with built-in fraud detection protocols

• Challenge illegitimate chargebacks

Card testing

Card testing is a type of fraud where someone makes small, low-value transactions with a stolen card to see if it works. Once the fraudster confirms the card is valid, they move on to larger purchases.

It doesn't just cause direct financial losses. Card testing also floods payment systems with fraudulent transactions. That means you have to spend valuable time reviewing suspicious activity, managing chargebacks, and reinforcing security measures. With effective fraud detection tools, you can spot these anomalies early and stay focused on serving legitimate customers.

How you can prevent card testing fraud:

• Implement CAPTCHA to prevent bots from making multiple transactions

• Set transaction limits and alerts for small, low-value transactions that could indicate card testing

• Limit the number of checkout attempts allowed from a single card or IP address within a certain timeframe

• Work with payment processors that have fraud prevention measures

• Use additional layers of authentication, such as 3D Secure (3DS), to verify the cardholder's identity

Skimming and e-skimming

Card skimming happens when a fraudster uses a skimming device or software, known as e-skimming, to steal customer payment information. When a customer inserts or swipes their card, the skimmer captures the card's data, which fraudsters can then use to create a counterfeit card or make unauthorised transactions.

A hacker could also get into your website and insert software that steals your customers' payment information. That puts your finances, reputation, and legal standing at risk. Strong website security measures can help you block these attacks and protect your customers' data, which helps keep them coming back.

How you can detect skimming fraud:

• Use secure payment gateways that are encrypted and compliant with PCI DSS (Payment Card Industry Data Security Standards)

• Require additional security information during checkout, like address verification (AVS) or CVV codes

• Have robust cybersecurity to prevent hacking attempts

• Use fraud detection software to identify fraudsters' attempts to checkout with skimmed cards

• Offer your customers contactless payment methods, which are less susceptible to skimming

Authorised push payment (APP) fraud

Authorised push payment (APP) fraud is a type of financial scam where a fraudster impersonates businesses, vendors, banks, or other trusted individuals to convince customers they're making a legitimate payment.

This type of fraud is rising and could cause US$6.8 billion in damage by 2027.³ On top of the considerable time and effort victims spend trying to recover, businesses also take a financial hit through higher operational overhead and the long-term effects of damaged customer trust.

How you can detect and prevent APP fraud:

• Inform customers immediately if you discover fraudsters attempting to impersonate your business

• Educate employees on APP fraud and how to avoid it

• Verify the identity of the vendor or supplier requesting the payment

• Remain wary of urgent payment requests

Account takeover fraud

Account takeover fraud happens when a fraudster gets access to a customer's account, whether that's a bank account, email account, or online shopping account. With unfettered access, they can steal account details or make unauthorised purchases using saved payment information. Nearly one in four consumers were victims of account takeover fraud (ATO) in 2024.⁴

For businesses, proactively preventing account takeover fraud is key if you want to avoid costly chargebacks and maintain positive customer relationships. By investing in robust security measures, you can safeguard your revenue and build stronger customer confidence.

How to detect and prevent account takeover fraud:

• Watch for repeated failed login attempts

• Track logins and look for IP addresses that don't match the customer

• Use device fingerprinting to spot sudden changes in IP, browser type, etc.

• Add an extra layer of security with multi-factor authentication (MFA)

• Monitor password reset requests

• Implement strong lockdown policies that limit access to compromised accounts

Card-not-present (CNP) fraud

Card-not-present fraud, or CNP fraud, happens when a fraudster gets someone's credit card information and uses it to make an online purchase. Fraudsters can get this information through phishing attempts, data breaches, or by buying stolen card information. This is one of the most common types of online payment fraud, and it often overlaps with other types, such as skimming and phishing.

In the US alone, CNP fraud in 2024 resulted in an estimated US$10.1 billion in losses⁵, and a significant portion of that shows up as costly chargebacks for businesses. By putting effective fraud prevention strategies in place, you can reduce these losses and protect your bottom line.

How to detect and prevent CNP fraud:

• Use firewalls to protect against data breaches

• Require customers to provide their CVV code at checkout

• Monitor transactions for unusual behaviour like low-value purchases

• Use fraud filters to identify potential cases of fraud

• Implement 3D Secure to authenticate transactions

Phishing and social engineering

Phishing attacks use fake emails, SMS messages, or websites to trick people into revealing payment credentials. A common example is a customer getting an email that looks like it's from your company and asks them to "verify" their payment details by clicking a link. That link takes them to a spoofed page that captures their card information.

Social engineering goes a step further by manipulating people directly. For example, a fraudster might call your finance team pretending to be a supplier and ask for a change to bank details. These attacks often act as the entry point for other fraud types like CNP fraud and account takeovers.

How to detect and prevent phishing and social engineering:

• Train employees to recognise phishing attempts and verify requests through a second channel

• Implement email authentication protocols like DMARC to reduce spoofed emails

• Educate customers about how you will (and won't) contact them

• Verify sender identities before acting on payment-related requests

• Use secure communication channels for sensitive financial information

Best practices to detect and prevent online payment fraud

Effective fraud prevention isn't about any single tool. It's about layering multiple defences, from ML-powered detection and 3DS authentication to tokenisation and continuous monitoring, so if one layer misses something, the next one catches it. Whether you're processing hundreds of transactions a day or thousands, here's what that looks like in practice.

Use machine learning and AI for real-time detection

Fraud detection technologies that analyse transaction patterns as they happen can help your business spot when cybercriminals are testing new fraud methods. Payment processors like Airwallex use machine learning to detect payment fraud more accurately and in real time.

By scoring each transaction against thousands of data points, including purchase amount, device type, location, time of day, and historical behaviour, these models identify suspicious activity before it turns into a chargeback. And because ML models learn from every transaction, they get more accurate as your volume grows. Businesses that have embraced these tools have achieved a 40% improvement in overall fraud detection.⁶

3D Secure (3DS)

One way to prevent fraud is to verify that your customers are who they say they are through 3DS. Instead of having a customer just enter a password, you can ask for an additional PIN, one-time password (OTP), or fingerprint before they complete the purchase.

To implement adaptive 3DS, you can work with a payment processor that supports this feature. Using this technology can help you balance security and user convenience in your payment processes.

Risk-based authentication

Risk-based authentication (RBA) is a more dynamic approach to authentication. It improves payment security by assessing and scoring each transaction to determine how likely fraud is, and then triggering additional authentication steps when risk is deemed high. RBA looks at factors like the customer's device, location, transaction amount, and historical behaviour.

Multi-factor authentication can do a good job of blocking unauthorised transactions, but applying it across the board can frustrate your customers and increase cart abandonment. That's where RBA stands out. It balances strong security with a smooth, low-friction checkout experience by only requesting 3DS when customers meet certain risk thresholds.

Tokenisation and encryption

Tokenisation replaces sensitive card data with a non-sensitive token, which is a random string of characters that's meaningless to anyone who intercepts it. Think of it like replacing your real house key with a one-time-use key that only works once. Even if someone copies it, it's useless.

When a customer saves their card for future purchases, tokenisation means you never store the actual card number. Even if your database is compromised, the tokens are meaningless to attackers. Payment encryption works alongside this by scrambling data in transit, so payment information can't be read even if it's intercepted between your customer's browser and your server.

Together, these technologies protect payment data at rest and in motion, reducing your exposure even if a breach occurs.

Digital wallets as a fraud reduction tool

Digital wallets like Apple Pay and Google Pay aren't just convenient for customers. They're also powerful fraud prevention tools. These wallets use built-in tokenisation, so the actual card number is never shared with merchants, and biometric authentication, such as fingerprint or face recognition, to verify the cardholder.

The result is that wallet transactions typically have lower chargeback rates because of that extra authentication layer. Offering digital wallet options at checkout can improve your conversion rates and reduce your fraud exposure at the same time.

Manage false positives

Overly aggressive fraud filters can hurt your business just as much as fraud itself can. A loyal customer places a larger-than-usual order, gets blocked at checkout, and takes their business elsewhere. Studies suggest that false declines cost merchants more than actual fraud, and the damage to the customer experience is harder to measure.

The answer isn't to loosen your fraud rules across the board. It's to use risk-based authentication that only escalates verification when risk is genuinely high. That way, you catch real fraud without frustrating legitimate customers.

Stay compliant with PCI DSS and regional regulations

The Payment Card Industry Security Standards Council (PCI SSC) has established guidelines to help secure cardholder data and prevent unauthorised access. These rules apply to anyone handling payment information, including your business, your payment processor, and your bank. PCI DSS compliance isn't just a checkbox. It's a baseline for protecting payment data through encryption, access controls, and regular security testing.

On top of global standards, your business should also comply with regional and local security regulations, like the EU's PSD3 or China's Anti-Telecom and Online Fraud Law. Choosing partners like Airwallex, which holds PCI DSS Level 1 certification, helps ensure your payment data is securely handled and protected, reducing the risk of data breaches.

Monitor continuously and respond quickly

The key to preventing fraud is maintaining, updating, and improving your security measures. That means regularly updating software, implementing multi-factor authentication, monitoring transactions, training staff, and staying informed on new fraud trends.

A global payments solution like Airwallex adds to this with advanced fraud detection and real-time monitoring. By scoring each transaction against thousands of data points in real time, Airwallex identifies and prevents fraudulent transactions instantly. This continuous monitoring for unusual patterns allows for immediate action and significantly reduces chargeback risks.

If you spot something suspicious, act fast:

• Flag the suspicious transaction with your payment processor or bank and contact the customer to verify.

• Once you've confirmed it's fraud, report it immediately and update your security measures to prevent similar incidents.

• Monitor your account for chargebacks and fraud claims, and ensure you're following all applicable regulations.

The quicker you detect fraud and take steps to address it, the better.

Cross-border fraud: What global businesses need to know

If you're selling to customers in the UK, Germany, and Japan, you're dealing with three different card networks, three sets of chargeback rules, and three different fraud risk profiles. Cross-border transactions bring complexity that domestic-only merchants don't have to deal with.

Some regions have higher CNP fraud rates than others. Chargeback dispute processes vary by country and card network. Currency manipulation, where fraudsters exploit exchange rate timing, adds another layer of risk. And applying consistent fraud rules across multiple payment methods and currencies is harder than it sounds.

For global merchants, that means your fraud detection needs to be trained on international transaction patterns, not just domestic ones. A transaction that looks suspicious in one market might be completely normal in another. The best approach is to work with a payment provider that processes payments across multiple regions and can apply localised fraud intelligence to your transactions.

Protect your payments with Airwallex

From ML-powered transaction scoring to adaptive 3DS and built-in PCI DSS Level 1 compliance, our Payments solution is designed to catch fraud without slowing down your legitimate customers. By analysing transaction patterns in real time, our fraud prevention engine identifies and blocks suspicious activity before it turns into a chargeback.

And, because we process payments across 180+ countries and 130+ currencies, our fraud models are trained on global transaction patterns, not just domestic ones. That means better detection for cross-border transactions and a more reliable payment experience for your customers, wherever they are.

Frequently asked questions

What's the most common type of online payment fraud?

Card-not-present (CNP) fraud is the most common type of online payment fraud. Cybercriminals can use phishing, skimming, and identity theft to get customer information and commit CNP fraud, which makes it a broad category that overlaps with many other fraud types.

How do I check for online payment fraud?

Look for common red flags, such as multiple password reset requests, numerous small-value orders, or a sudden increase in chargebacks. You can also use advanced tools like machine learning and AI to help you identify suspicious activity quickly.

How does machine learning help detect payment fraud?

Machine learning models analyse thousands of data points per transaction, including purchase amounts, device types, locations, and time of day, and look for patterns that signal fraud. Because these models learn from every transaction, they become more accurate over time and can adapt to new fraud tactics faster than rule-based systems alone.

Can online fraud money be refunded?

It depends on the type of fraud and how quickly you act. Cardholders can typically dispute fraudulent charges through their bank's chargeback process. For merchants, though, chargebacks mean bearing the cost of the fraud plus additional fees, which is why prevention is more cost-effective than recovery.

What's the difference between fraud detection and fraud prevention?

Fraud detection identifies suspicious transactions as they happen, whilst fraud prevention stops fraud before it occurs. In practice, the two work together: detection systems flag risky transactions, and prevention tools, like 3DS or transaction blocks, act on those flags to stop fraud in its tracks.

Sources and references

• https://www.jpmorgan.com/content/dam/jpm/commercial-banking/insights/cybersecurity/highlights-afp-2022-payments-fraud-and-control-report.pdf

• https://www.chargeback.io/blog/chargeback-statistics

• https://www.aciworldwide.com/app-fraud

• https://spycloud.com/blog/cybersecurity-industry-statistics-account-takeover-ransomware-data-breaches-bec-fraud/

• https://www.emarketer.com/content/spotlight-us-card-payment-fraud-losses-forecast-2022

• https://resources.nvidia.com/en-us-cross-industry-briefcase/how-ai-helps-fight-fraud