Use case summary
Corefy's Firewall is a customizable antifraud engine that checks every incoming and outgoing payment in real time against rules you set, your own allow/block lists, and external scoring tools like Sift, MaxMind, or Ravelin. Each transaction is authorized, challenged with 3DS, or blocked before it reaches a provider — one rule set covering your whole payment stack.
- Payment Manager
- Payment Ops
Why catching fraud after authorization costs the most
Fraud that reaches authorization has already won half the battle. Once a fraudulent payment is approved, recovering the money means fighting a chargeback weeks later — after the goods have shipped, the service has been used, or the funds have moved on. Merchants were projected to lose around $53 billion to online payment fraud in 2025, and in the US the total cost of fraud reaches $4.61 for every $1 lost once chargeback fees, lost goods, and operational costs are counted. A single approved fraudulent transaction rarely costs only its face value.
The instinct is to bolt on an external fraud-scoring tool. But a single tool rarely fits every business, and routing every transaction out to an external service has a hidden cost: Corefy's own testing found that even a 0.05-second delay sending data to an external antifraud system measurably lowers conversion. So teams face a bad trade — screen hard and lose good customers to latency and false positives, or screen lightly and let fraud through. And whichever they choose, the fraud logic usually lives in code, so tuning it against a new fraud pattern means a developer ticket and a release, always a step behind the fraudsters.
How to screen every payment before it's authorized
Firewall sits in the authorization path as a decision layer: every payment is evaluated against your rules before it's sent to a provider, and only transactions that pass proceed.
- 1
Screen with an attribute-based rule engine
The Firewall evaluates each incoming and outgoing payment in real time against rules built on transaction attributes — amount, geography, IP, card details, velocity, and more — using the same readable condition logic as Corefy's routing engine.
- 2
Decide with a decision tree
Rules and lists combine into a decision tree that determines the legitimacy of each payment and routes it to an outcome: authorize, challenge, or block. You design the tree around your own risk profile rather than accepting a fixed model.
- 3
Use your own allow and block lists
Maintain lists of known-bad users, cards, IPs, or countries so repeat offenders are stopped automatically and trusted customers pass without friction. Lists update from the dashboard as your risk picture changes.
- 4
Bring your external scoring tools into one flow
Firewall interacts with third-party scoring and fraud services like Sift, MaxMind, and Ravelin, so their signals feed your decision tree instead of running as a separate, disconnected check. You keep the tools you trust; Firewall orchestrates them.
- 5
Apply 3DS selectively
Instead of forcing 3DS on everyone, enable it only for transactions your rules flag as risky, so authentication lands where it's needed and stays out of the way where it isn't.
- 6
Tune without a release
Because rules and lists are dashboard configurations, responding to a new fraud pattern is a change your risk team makes directly, effective immediately, closing the gap that lets fraudsters exploit the lag of a code-deploy cycle.
What you get
Fraud gets stopped where it is cheapest.
Losses prevented
Blocking a fraudulent payment before authorization avoids the chargeback, the fee, and the recovery effort entirely.
Screening that protects conversion
A native engine avoids the latency penalty of round-tripping every transaction to an external service, and selective 3DS keeps friction off good customers, so fraud control stops costing you legitimate sales.
Your tools, orchestrated together
External scoring services and your own lists feed one decision tree, so signals combine into a single verdict rather than sitting in separate silos.
A risk team that keeps pace
Rule and list changes ship from the dashboard, so your defenses adapt to new patterns the day you spot them.
A high-risk PSP that automated fraud screening with lists and rules
A PSP providing payment processing to high-risk gambling and betting clients was repeatedly hit by fraudulent transactions that threatened both their finances and their reputation. Working with Corefy, they built a comprehensive blocklist of users previously involved in fraud and configured Firewall to automatically stop payments from those users. A decision tree of rules and lists, customized to their business, now determines the legitimacy of each payment in real time, screening fraud out before it reaches a provider.