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Definition

In POST /v3/verify responses, the identity object includes:
FieldRole
assuranceLevelTier such as AL-1, AL0, AL1, AL2, or AL3. Higher tiers indicate stronger confidence in the association between the phone number and the identity.
reasonsOne or more reason codes from the tables below (for example -1A, 1B).
Tiers are ordered from lowest (AL-1) to highest (AL3).

Reason codes

AL-1

Reason codeDescription
-1AToo many identities bound to a single phone number.
-1FPremium rate number globally or listed on the US Override Services Registry (OSR) registry.
-1GOnline rentable temporary eSIM or VoIP number.
-1HOnline rentable temporary eSIM or VoIP number, with high activity. This indicates fraudulent activity.

AL0

Reason codeDescription
0BCountry doesn’t give behavioral data.
0CAssigned number with no behavioral activity.
0DShort tenure, no activity. Reclassifies to AL0E if activity appears.
0EShort tenure with behavioral activity present.
0FActivity volume exceeds normal human thresholds.
0GPagers or other non-standard line types. Behavioral signals incompatible with standard identity verification.

AL1

Reason codeDescription
1AEnough ownership tenure and longitudinal human behavior.
1BTenure and longitudinal human behavior with Prove binding phone to a specific identity, superseding AL1A.
1DLow longitudinal behavior but human signals such as ports, calls, or logins indicate not an eSIM bot.

AL2

Reason codeDescription
2AProve has seen this phone and identity before at moderate-to-high confidence.
2BProve corroborated data across more than one identity data source.

AL3

Reason codeDescription
3AProve has seen this phone and identity before at high confidence, this is this person’s primary number.