Your fraud tool could be hurting your best customers. You might not even know it.
That $500 order that never went through? The returning buyer who disappeared? The VIP client who suddenly had “payment issues”? They may have been blocked—not by their card, not by your checkout—but by Stripe Radar.
Stripe Radar is built to fight fraud. And for the most part, it does its job. But sometimes it goes too far. It flags good customers, blocks legit payments, and quietly turns away people who were ready to buy. No warning. No alert. Just a dropped transaction and a missed opportunity.
Let’s talk about how Stripe Radar works, where it goes wrong, and what you can do to stop it from quietly killing your revenue.
When Fraud Tools Get It Wrong
Fraud detection tools are built to protect businesses. They use algorithms, pattern recognition, and machine learning to stop stolen credit cards and suspicious transactions before they hurt your bottom line. But what happens when those same tools flag loyal, legitimate customers?
That’s the reality many merchants are facing with systems like Stripe Radar. While it's designed to detect and prevent fraud, it sometimes makes decisions that quietly cost businesses money without any clear warning or path for recovery.
Stripe Radar in a Nutshell
Stripe Radar uses machine learning models trained on billions of transactions to score each payment for risk. Every card attempt gets a risk score, and based on that, it may be automatically blocked, flagged, or held for manual review.
Radar includes features like:
- Device fingerprinting
- IP reputation analysis
- Card behavior profiling
- Custom rules and lists
- SCA (Strong Customer Authentication) support
By default, Radar may automatically block high-risk payments or ones that match certain fraud patterns.
But here’s the catch: the system isn’t perfect.
False Positives = Lost Revenue
Plenty of forums and merchant discussions paint a clear picture—Stripe Radar can be overly aggressive, especially with customers who:
- Use VPNs or privacy tools
- Travel frequently
- Continuously make high-value or repeat purchases
- Use mismatched billing/shipping addresses
- Have new cards or banks without a long transaction history
These scenarios are common with your best customers—people who spend more, come back often, or care about online privacy. Yet Radar may score them as high risk, resulting in silent blocks or payment failures that the customer never even sees.
No Alert, No Appeal
What makes it worse is the lack of feedback. Merchants often don’t know when a transaction is blocked unless they:
- Manually dig through the Stripe dashboard
- Monitor logs and alerts
- Hear from the customer directly (if they bother to reach out)
There’s no built-in appeal process. Stripe doesn’t notify merchants that a legitimate customer was blocked unless the merchant does the digging. That means you could lose loyal customers without ever knowing why.
How Radar Scores Payments
Radar uses a risk score system between 0 and 100. A higher number means greater risk. You can set thresholds to block payments above a certain score, but the scoring model isn’t publicly documented in full.
Some of the key signals include:
- Card issuing country vs. customer IP location
- Velocity (too many attempts, too quickly)
- 3D Secure completion status
- Known blacklists
- Behavioral trends across the Stripe network
It’s powerful tech. But it can also misclassify, especially when a good customer doesn’t look “normal” to the algorithm.
What Merchants Are Saying
A lot of merchants have given their feedback across multiple online platforms. Let’s take a look at what they have to say about Stripe Radar:
“One of our top customers couldn’t check out for a week. Turns out Radar was blocking them for using a travel VPN.”
“Radar blocked a $900 order from a returning customer. They used the same billing address as always.”
“We had a 5% drop in conversion. Looked into it and found dozens of failed payments from repeat buyers.”
These aren’t isolated cases. The silent nature of the block makes it hard to quantify the damage. And many businesses just chalk it up to customer churn or drop off.
What You Can Do
If you’re using Stripe Radar, it’s important to be proactive. Here are a few steps to reduce false positives:
1. Monitor Your Declines
Regularly review declined payments in your Stripe dashboard. Filter by reason code and look for patterns like blocked_by_radar.
2. Adjust Your Radar Rules
Stripe lets you create custom Radar rules. You can allow-list certain behaviors or lower the sensitivity on specific transaction types. Just be cautious because you don’t want to open the door to real fraud.
3. Use Radar for Teams
If you upgrade to Radar for Teams, you get more control over your risk settings, rule management, and manual review process. This isn’t free, but it’s often worth the investment if you’re dealing with higher volume or customer complaints.
4. Allow SCA Where Possible
Strong Customer Authentication can reduce fraud risk and increase authorization rates. If SCA is available for a given card and region, enable it.
5. Communicate with Customers
Make it easy for customers to contact you if their payment fails. If you hear a “my card didn’t work” message more than once, investigate—don’t just assume it was the customer’s fault.
Final Thoughts
Stripe Radar does what it’s built to do—catch fraud. But that safety net can also catch your most valuable customers if you’re not careful. It’s silent, it’s automated, and it doesn’t always give you a heads-up.
If you rely on Stripe, take time to understand what’s happening behind the scenes. A blocked customer is a lost customer. And most of them won’t try twice.
Frequently Asked Questions
What does “blocked_by_radar” mean in Stripe?
This means Stripe’s fraud system flagged a payment as high risk and blocked it before authorization. The customer likely never saw a message.
Can I appeal a Radar block?
No, Stripe doesn’t offer a formal appeal process for individual blocks. You can review logs, adjust your rules, and allow-list certain customers manually.
Is Stripe Radar too aggressive?
For some merchants, yes. The default settings can be strict, and the machine learning model may flag edge-case behavior that isn’t actually fraudulent.
What’s the difference between Radar and Radar for Teams?
Radar (included with Stripe) offers basic fraud protection. Radar for Teams adds advanced tools like custom rules, review queues, and risk score tuning.
Looking to Cut Fraud Without Losing Revenue?
Chargeblast helps merchants get chargeback protection without compromising on customer experience. If Stripe Radar’s silent blocks are costing you money, it’s time to look at smarter tools that flag real fraud and let good customers through. We’ll show you what’s being missed—and how to fix it.
