In this guide · 7 sections
Short answer
Start with Stripe's defaults: Radar Lite is included with standard pricing. Upgrade to Radar Plus (S$0.10 per screened transaction, Oct 2026) only if you need custom rules, manual reviews or risk scores. Prefer Request 3D Secure and Review rules over Block rules, and test each rule first.
Stripe Radar plans and prices in Singapore
Stripe's Radar pricing page for Singapore lists four plans. Radar Lite is included for businesses on standard payments pricing; the others are charged per screened transaction.
| Plan | Price (SGD, Oct 2026) | What you get |
|---|---|---|
| Radar Lite | Included with standard pricing | AI fraud prevention for card payments, card testing protection, fraud alerts |
| Radar Standard | S$0.08 per screened transaction | AI screening across all payment methods, default rules and lists, fraud analytics, risk levels |
| Radar Plus | S$0.10 per screened transaction | Adds risk scores 0 to 99, custom rules and backtesting, manual reviews, adaptive 3D Secure |
| Radar Pro | S$0.12 per screened transaction + S$0.006 per abuse event | Adds dynamic risk thresholds and abuse signals: free trial, bot, multi-account |
If you sell online with cards only and have few disputes, Radar Lite is usually enough. Move up when you see repeated fraud patterns your defaults miss, or when you need a person to review risky orders before shipping.
What Stripe's default rules already do
Stripe's Radar rules documentation lists the defaults. Payments Stripe considers highest risk are blocked, and Stripe places payments with an elevated risk of fraud into review. Additional default rules use account-level risk models.
Stripe also offers built-in rules to block payments that fail the issuer's CVC or postal code check, unless Stripe judges the payment low risk. A payment can still succeed when CVC or address checks fail, because the card issuer decides, so these rules are worth reviewing if you see disputes on cards with failed checks.
Five custom rules worth considering
Custom rules use the syntax {action} if {attribute} {operator} {value}. These examples come from Stripe's documentation and rules reference; all need Radar Plus or Pro.
| Rule | What it does | Watch out for |
|---|---|---|
| Request 3D Secure if :risk_level: != 'normal' and :amount_in_usd: > 25 | Asks for 3DS on elevated or high-risk payments over about US$25 | Adds a step for some genuine buyers |
| Request 3D Secure if is_missing(:seconds_since_card_first_seen:) | 3DS for cards never seen on your account | Add a risk_level condition to reduce friction |
| Review if :card_country: != :ip_country: | Flags payments where card and IP countries differ | Tourists and expats trigger it; review, do not block |
| Block if :card_country: in @card_countries_to_block | Blocks card countries on a custom list | Only if you never sell to those countries |
| Block if :is_3d_secure: and not :is_3d_secure_authenticated: | Blocks payments where 3DS was attempted but failed | Accepts wallets and cards without 3DS |
Card-testing bursts need velocity rules, such as limiting how many cards one email or IP can try per hour. Our guide to fixing a card testing attack on Stripe covers those rules and the CAPTCHA and rate-limit settings that go with them.
3D Secure and the review queue
Stripe says that if 3D Secure authenticates a payment, liability for fraud-related disputes typically shifts from you to the card issuer. Request 3DS rules only apply with Stripe Checkout, Payment Intents or Setup Intents, and they are evaluated before review, block and allow rules. Asking for 3DS on every payment lowers conversion, so target it at risk. Our 3D Secure explainer covers how it works for customers.
The review queue is a list of payments Radar or your rules flagged. Stripe notes that payments in review have usually already been processed, so the decision is whether to approve, refund, or refund and mark as fraudulent. For physical goods, check flagged orders before you ship; for services, before you deliver.
Check the queue daily
Set a time, such as before the courier pickup, to clear reviews. Unreviewed fraud becomes a dispute weeks later.
Look at the whole picture
Compare billing and shipping addresses, email age, IP country and order size. One odd signal is normal; several together are not.
Contact the customer if unsure
A short email or call to the number given often settles it. Fraudsters rarely answer.
Refund and mark as fraudulent when confident
This refunds the payment and feeds Stripe's models, which helps future screening.
Avoiding false positives when you add rules
A bad block rule costs more than most fraud, because you never see the customers it turned away. Stripe's documentation gives a safe rollout method:
Before you switch a rule on
If a dispute does arrive, our Stripe dispute and chargeback guide covers the evidence that wins.
Do it yourself or get help?
If your volumes are modest and disputes are rare, the defaults plus Stripe Checkout are usually enough, and you can add a review rule or two yourself. Help is worth it when you are under a card-testing attack, disputes are climbing, or your checkout is custom-built and not passing the signals Radar needs.
IT Sorted is a Singapore-based team of developers with over 10 years of experience. Online Payment Setup (S$290) sets up Stripe or HitPay in your name with PayNow, cards and wallets on your website, so Radar receives the payment data it relies on. Stripe's per-transaction and Radar fees are charged by Stripe.
Frequently asked questions
Partly. Stripe's Singapore Radar pricing page says Radar Lite, with AI fraud prevention for card payments, card testing protection and fraud alerts, is included at no additional charge for businesses on standard payments pricing. Radar Standard, Plus and Pro cost S$0.08, S$0.10 and S$0.12 per screened transaction as of October 2026.
Yes. Stripe's plan comparison lists custom rules, backtesting, custom allowlists and blocklists, manual reviews, risk scores and adaptive 3D Secure as included in Radar Plus and Radar Pro, not in Radar Standard. Standard gives you Stripe's default rules, default lists, fraud analytics and risk levels across payment methods.
Usually not outright. In Singapore many genuine buyers are tourists, expats or people on VPNs, so a block rule turns away real sales. Use a Review rule or request 3D Secure for those payments instead, and only block if your own disputed payments show that pattern clearly.
Stripe says that when 3D Secure authenticates a payment, liability for fraud-related disputes typically shifts from you to the card issuer. It does not cover non-fraud disputes such as goods not received. Requesting 3DS also does not guarantee the issuer performs it, and using it on every payment can lower conversion.
Stripe says payments in review are usually already processed, unless you capture later. You then approve the payment, refund it, or refund it and mark it as fraudulent. Check reviews before you ship goods or deliver services. You cannot manually review ACH or SEPA Direct Debit payments.