Recently ported phone numbers indicate 4x higher fraud risk. Learn how MNP lookup and real-time portability monitoring stop account takeover, SIM swap attacks, and porting fraud—blocking 89% of attacks while protecting legitimate carrier switchers.
Mobile Number Portability (MNP) allows consumers to switch carriers while keeping their phone number—a consumer protection right in 90+ countries. While MNP promotes carrier competition and consumer choice, it creates a temporary vulnerability window fraudsters exploit. When a number ports, the new carrier lacks historical relationship data, security protocols reset, and fraud detection systems interpret the change as normal consumer behavior.
Fraudsters exploit this window through two primary methods: (1) porting victim numbers to gain control of their accounts (account takeover), and (2) using newly ported numbers to establish fake accounts that appear legitimate. The 30-day period after porting represents peak vulnerability—recently ported numbers have 4x higher fraud rates than established numbers.
MNP lookup queries centralized portability databases that track every number port within a country. In the US, NPAC (Number Portability Administration Center) maintains 1 billion phone number records across 1,600+ service providers. Globally, each country operates an MNP registry or centralized database that carriers query to route calls to the correct network.
Real-time MNP lookup returns three critical data points for fraud detection:
The carrier that originally issued the number. Discrepancies between original and current carrier indicate recent porting. Numbers ported multiple times (carrier hoppers) have 6.2x higher fraud rates.
The carrier currently servicing the number. Real-time carrier detection is essential for SMS routing and fraud prevention. Rapid carrier changes (multiple ports within months) signal fraudulent behavior.
The exact date when the number was last ported. Time-based risk assessment: numbers ported within 7 days are critical risk, 8-30 days elevated risk, and 30+ days treated as established. Complete porting history reveals carrier hopping patterns.
{
"phone_number": "+14155551234",
"is_valid": true,
"original_carrier": "Verizon Wireless",
"current_carrier": "T-Mobile USA",
"is_ported": true,
"porting_date": "2026-01-15",
"days_since_porting": 16,
"port_count": 2,
"risk_score": 67,
"risk_level": "elevated",
"recommendation": "additional_verification"
}Fraudsters port victim numbers to carrier-controlled SIMs, then intercept OTP codes to bypass 2FA and compromise accounts. Banking and crypto platforms face 73% of SIM swap attacks within 7 days of victim number porting.
Detection: Monitor existing customer numbers for porting events and trigger re-verification
Fraudsters port numbers to establish "aged" phone identities for fake accounts. Recently ported numbers appear legitimate to basic validation but lack historical usage patterns. SaaS platforms report 52% of promo abuse involves ported numbers.
Detection: Flag registrations from numbers ported within 30 days for additional verification
The 24-72 hour porting transition creates security gaps. Old carrier security controls transfer while new carrier establishes protocols. Fraudsters time attacks during this window when fraud detection systems are recalibrating.
Detection: Implement enhanced monitoring during known porting windows
Sophisticated fraudsters repeatedly port numbers to evade detection—each port resets carrier-specific fraud flags and creates new device fingerprints. Numbers ported 3+ times within 6 months have 8.4x higher fraud rates.
Detection: Analyze complete porting history and flag rapid carrier changes
Fraud risk correlates directly with time since porting. Numbers ported within 7 days represent peak risk (12.3% fraud rate), declining to baseline (3.1%) after 30 days. This predictable pattern enables time-based risk scoring that blocks fraud while accommodating legitimate carrier switchers.
Optimal strategy: tiered response based on porting age. Block registrations from numbers ported within 7 days, require additional verification (document upload, video call) for 8-30 days, and treat ported over 30 days as normal risk. This achieves 89% fraud reduction while allowing 92% of legitimate ported users through without friction.
| Days Since Porting | Fraud Rate | Risk Level | Action |
|---|---|---|---|
| 0-7 days | 12.3% | Critical | Block Registration |
| 8-30 days | 6.7% | Elevated | Additional Verification Required |
| 31-90 days | 4.2% | Moderate | Enhanced Monitoring |
| 90+ days | 3.1% | Baseline | Standard Risk Assessment |
Most phone validation happens at registration or transaction time. Porting fraud requires continuous monitoring of existing customer numbers. When a known customer's number ports, it triggers immediate security response: freeze account, require re-verification via alternative channel, notify user of suspicious activity.
Leading financial institutions implement webhook-based porting alerts. When MNP databases detect porting events for monitored numbers, real-time notifications trigger automated security workflows. This prevents account takeover during SIM swap attacks—blocking 89% of attempts before fraudsters can access accounts.
Regular carrier lookup identifies the current carrier servicing a number. MNP lookup provides additional context: the original carrier, porting date, and complete porting history. This historical data is essential for fraud detection because recently ported numbers have 4x higher fraud rates. MNP databases track every porting transaction within a country, while carrier lookup only provides the current state. Both queries return in 50-200ms, enabling real-time fraud prevention without user experience impact.
MNP is available in 90+ countries including all major markets. The US, Canada, UK, EU, Australia, Japan, and most of Latin America mandate MNP by law. Some emerging markets have limited or no portability (parts of Africa, Middle East, Southeast Asia). MNP lookup APIs cover countries where portability is available, returning portability status along with carrier information. In non-MNP countries, carrier lookup alone provides sufficient fraud detection since numbers cannot switch carriers.
MNP databases update in near real-time, typically within minutes of a completed port. The 24-72 hour porting process involves validation between carriers, but once approved, the porting event registers in MNP databases immediately. Real-time monitoring systems detect porting events within 5-15 minutes of completion. This rapid detection is critical for preventing SIM swap fraud—fraudsters gain control of the number during the porting window, but monitoring systems trigger security alerts before they can exploit compromised accounts.
Provide alternative verification channels: email verification, document upload (utility bill or ID showing name match), video call verification, or knowledge-based authentication. Legitimate users can prove identity through multiple channels. The 7-day block only applies to new registrations—existing customers who port numbers trigger re-verification workflows but aren't permanently locked out. Most legitimate users complete alternative verification within 24-48 hours. If users report false positives, adjust risk scoring thresholds or create whitelist programs for verified users.
MNP lookup typically costs 20-30% more than standard carrier lookup due to database access fees and portability registry charges. However, the ROI is substantial: preventing one account takeover ($2,400 average loss) covers 10,000 MNP lookups. Implement tiered validation: use standard carrier lookup for low-risk registrations, MNP lookup only for high-value accounts or suspicious patterns. Real-time porting monitoring for existing customers costs $0.003-0.005 per monitored number monthly—compared to $127K average fraud loss for unprotected platforms.
Real-time MNP lookup and portability monitoring. Block 89% of porting attacks while protecting legitimate carrier switchers.
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