# Multi-Accounting

## Only allow signing up once

Aggregate the number of accounts created per device, IP, or credit card and block when it exceeds a threshold.

### Real-time blocking

Rules execute in milliseconds to block multi-accounting inline without noticeable delay.

### Custom definitions

Define multi-accounting your way using advanced filtering and real-time velocity queries.

### Granular analytics

Leverage BI-grade analytics to expose multi-accounting and fraud rings at scale.

### Data enrichment

Enriched with device intelligence, risk scores, velocity metrics, and much more.

## Define multi-accounting using custom logic

Castle lets you use advanced filtering, real-time velocity queries, and custom lists to segment out multi-accounting with high precision.

- deny

- Promo Code exists

and

Unique count of User ID by Device Fingerprint in the last 3 mo is > 3  or  Unique count of User ID by IP Address in the last 15 min is > 10

## Action on multi-accounting in real-time

Rules execute in milliseconds and can be used to adapt the user experience based on risk in real-time.

- deny

- Abuse Score is > 90 and Disposable Email is true and Count events Registration by Device Fingerprint in the last day is > 3 or Signals include Blocked country

- Add User ID Warned Account Sharers
- Remove User ID Allowed Users
- Send webhook https://hooks.zapier.com/hooks/catch/4378238094/ch3dka
- Send to Slack #security-alerts

### Real-time decisions

Assessments of data like user count per device or hourly failed logins executed in the blink of an eye.

### Inline blocking

Initiate request blocks or step-up verifications anywhere in your app without disrupting the user experience.

### Alerts & notifications

Ensure your team and users stay informed with triggered Slack notifications or webhooks.

## A holistic view of multi-accounting

Harness the power of BI-grade analytics to expose multi-accounting attacks and unravel fraud rings with precision.

### Example Events

- User Activity Timestamp: Sat, Aug 8 07:59:08, Policy: Challenge, Event: Login Attempted, User: kevin.qfanjul@gmail.com, Location: Spain, Connection: Telefonica de Espana, Device: Chrome on Windows 10

- User Activity Timestamp: Sat, Aug 8 07:59:08, Policy: Deny, Event: Registration Attempted, User: oleg.kalinovskiy75@gmail.com, Location: Ukraine, Connection: Kyivstar, Device: Chrome on Windows 10

- User Activity Timestamp: Sat, Aug 8 07:59:08, Policy: Deny, Event: [ScAuth] Attempted Login, User: themba.ndlovu@gmail.com, Location: South Africa, Connection: Starlink, Device: Chrome on Windows 10

## Enrichment

### All the data you need to pinpoint multi-accounting

Every interaction is enriched with comprehensive device intelligence, risk scores, location data, and much more.

### Risk Scores

Out of the box risk scores for account abuse, account takeover, and bot abuse.

### Velocities

Compute personalized signals based on real-time metrics like counts, sums, averages, and more.

### Device fingerprinting

Persistent device identifiers resilient to storage resets and resistant to privacy plug-ins.

### Bot detection

Identify bot actions via bot scores, headless indicators, or velocity and rate limit checks.