Vonage explores how real-time mobile identity signals, like SIM swaps, porting activity, and subscriber type, can strengthen fraud prevention
Fraudsters are getting smarter. Your risk scoring should too. By combining mobile identity signals – like SIM swap detection, porting activity, and subscriber type – with your existing fraud tools, you can score risk in real time before every transaction.
That means fewer chargebacks, smarter step-up checks, and a better experience for trusted users.
A transaction might look clean on the surface, right device, right location, right time. But underneath, something’s off. The SIM card was swapped 12 hours ago.
The subscriber is prepaid and new to the network. The phone number just changed carriers. These signals won’t show up in a standard risk check. But they’re often the difference between a good user and a bad actor.
Fraud has evolved past simple red flags. Attackers mimic legitimate behavior, automate high-volume attempts, and exploit gaps in static checks. For risk teams, the question isn’t just “Is this transaction safe?” It’s “What don’t I see?”
Treating every user the same means opening the door to losses. You need a better way to know who you’re dealing with, before the transaction even happens.
Risk scoring helps answer that question by analysing digital behaviour, device patterns, and, increasingly, mobile identity signals that reveal what’s really going on behind the screen.
These are the questions modern fraud teams have to ask. The answers start with real-time, data-driven insights, where every interaction is scored, and every score is backed by intelligence that goes beyond the basics.
In many cases, that includes smarter two-factor authentication (2FA) when signals suggest added risk
Risk scoring is a way to quickly evaluate how safe, or risky, a transaction might be. It assigns a numerical score based on data points like user behaviour, device type, location, and transaction history. The higher the score, the higher the risk.
This system helps fraud teams decide how to handle each transaction:
At its best, risk scoring works in real time and adapts to each situation. It’s designed to be flexible: You can change thresholds, combine it with other rules, or use it alongside your current fraud detection tools.
The process starts by gathering data about the transaction. This includes the device used, location, user history, phone number, email address, and more.
Advanced systems may also include mobile identity data, like SIM card activity or carrier type, for a deeper look. These identity signals add important context that static data alone can’t provide.
Machine learning models review this data to find unusual patterns. Is the user logging in from a new country? Did their SIM just change? Are they using a high-risk email domain? These signals all help estimate the likelihood of fraud.
The system gives the transaction a score, usually on a scale like 0 to 100. The score reflects how risky that activity appears. For example:
Once scored, the transaction moves through a decision engine. Depending on your risk settings, you can allow, block, flag for review, or require extra verification.
Transaction risk scoring focuses on one event at a time, like a login, money transfer, or purchase. It’s great for stopping fraud before it happens.
Merchant risk scoring looks at the business itself. It reviews factors like industry type, sales history, refund rates, and chargebacks. This is often used by payment platforms and marketplaces.
Both types work better when they’re powered by high-quality, real-time data, especially signals tied to user identity, not just transaction history.
Most fraud detection tools focus on what a user does, how they move, what they click, or where they log in. But what if you could also understand who they are from the network itself?
Mobile identity data adds that extra layer. It pulls real-time signals from the mobile carrier to provide clues about whether a user’s phone number, SIM card, or device behaviour is trustworthy.
These signals are invisible to the user, but they can be highly effective in spotting fraud that looks normal on the surface.
These signals don’t interrupt the user journey. They run in the background, scoring trust in real time. That means you can add smarter risk checks without adding more steps.
Used with a standard scoring model or decisioning engine, mobile identity data helps spot high-risk users early, before a transaction is processed or an account is created. It’s especially valuable when behavioural data is limited, like during onboarding or a new device login.
When a phone looks clean but was swapped yesterday, do you still let it through?
That’s the kind of question these signals help answer.
Risk scoring works best when it goes beyond one-size-fits-all rules. With real-time identity signals, you can apply smarter filters that react to context, catching fraud before it happens and keeping trusted users moving forward.
Here are three common scenarios where mobile identity scoring makes a difference:
A new user signs up from a device that’s never been seen before. The phone number checks out on the surface — but mobile identity data shows it’s tied to a recently activated prepaid SIM. There’s also evidence of past porting activity.
With standard KYC, this might slip through. But with mobile risk scoring in place, the system flags the user for further review or additional verification — stopping fraud before the account gets created.
A user initiates a large funds transfer within a financial app. Their phone number is familiar, but the SIM was swapped 18 hours ago and the user is now roaming in a new country.
Mobile signals push the risk score higher, automatically triggering a second factor of authentication. The system keeps the transaction secure without blocking legitimate users who show no signs of elevated risk.
Dozens of verification attempts flood your system from different numbers. Each one looks fine individually, but identity scoring reveals they’re all new SIMs on the same network, purchased within a 48-hour window.
This pattern indicates synthetic fraud or bot-driven abuse. The system raises the risk scores, blocks further attempts, and alerts the fraud team to investigate, all without manual review.
These use cases show how telco-powered signals help fine-tune decisions, whether you’re onboarding a user, evaluating a transaction, or stepping in before fraud spreads.
Most fraud tools rely on patterns from the past. They look at historical transactions or user behavior and try to predict what’s risky. But fraud moves fast, and when detection lags behind, losses add up.
That’s where real-time signals make the difference.
Mobile identity data gives you a current snapshot of the user’s phone, SIM, and network activity. It doesn’t just tell you what happened, it tells you what’s happening right now. This helps reduce false positives, speed up safe users, and catch risk early.
Here’s why that matters:
Many risk teams struggle with friction. They either ask for too much information up front or hold back until it’s too late. With real-time identity scoring, you don’t have to choose between security and experience – you get both.
Adding identity risk scoring doesn’t mean rebuilding your system. You can start small, connect to a single API with identity signals, and begin using those signals where they make the most impact — without slowing your teams down.
You don’t need to swap out your fraud stack. Identity scoring works as a layer on top — giving you more context at key decision points. Use it to fine-tune your rules, score new interactions, or strengthen existing models.
It’s available via a single API and can return results in milliseconds. That means faster reactions, smarter actions, and less friction for users who deserve none.
For teams looking to layer in traffic-level controls, tools like Fraud Defender can help detect and limit SMS or voice-based abuse.
Fraud isn’t just about what users do. It’s about who they are – and what signals they leave behind.
With mobile identity signals like SIM changes, porting events, and subscriber type, fraud teams can see beyond surface-level behaviour and uncover hidden risks.
These signals reveal if a user is likely to be legitimate or potentially high-risk, even when everything else looks normal.
Real-time identity signals help risk models adapt faster. Instead of relying on static rules or historical patterns alone, teams can use fresh network data to detect fraud before it happens, reduce false positives, and improve decision-making across the payment flow.
This is what modern fraud prevention looks like: flexible, low-friction, and driven by real-world behaviour, evaluated in the moment it matters most.
This post has been re-published by kind permission of Vonage - view the original article.
Reviewed by: Robyn Coppell