Query Parameters

Key	Description	Required	Example
tnList*	JSON list of phone numbers to lookup, limit 100	Yes	{"tnList":[{"tn":"5556789001","date":"2026-02-11"},{"tn":"5556789002","date":"2026-02-11"}]}
sys_id	Your TxTRIA sys_id	Yes	ACfc98e7b0aae031b9h...
auth_token	Your TxTRIA account token	Yes	c74eac89884a126a2c...

*All phone numbers (tn's) must be 10 digit numbers. Number NPA & NXX cannot be less than 200. Number check from date (date) must be format YYYY-MM-DD and cannot be today or in the future. Recommended date to check against would be suspected or actual subscribe/consent date. API will return for each phone numbner `disconnected`=>`yes|no` (Yes means from the start date provided, a disconnection occured)

Request Validation Requirements

The Reassigned Number Lookup API performs strict validation on all submitted telephone numbers and query dates before processing.

Telephone Number (TN) Requirements

• All telephone numbers (tn) must be valid North American Numbering Plan (NANP) numbers consisting of exactly 10 numeric digits.
• Numbers must be submitted without formatting characters such as parentheses, spaces, periods, or hyphens.
• The Numbering Plan Area (NPA) and Central Office Code (NXX) must each be greater than or equal to 200.
• Invalid, reserved, or improperly formatted telephone numbers will be rejected and returned in the API error response.

Valid Examples

7345551671
4165551234
3135559876

Invalid Examples

07345551671   // More than 10 digits
17345551671   // More than 10 digits
1234567890    // Invalid NPA
7340991671    // Invalid NXX
(555)799-1671 // Formatting characters not allowed

Date Requirements

• The lookup date (date) represents the historical reference point from which reassigned number activity will be evaluated.
• Date format must be YYYY-MM-DD (ISO 8601 date format).
• The date cannot be today's date.
• The date cannot be a future date.
• The date should represent the subscriber acquisition date, opt-in date, consent date, account creation date, or another date from which contact authorization is being evaluated.

Valid Examples

2024-01-15
2025-06-01

Invalid Examples

01/15/2024
2024-1-15
2026-12-24 (future date)
2026-06-24 (today)

Response Interpretation

For each submitted telephone number, the API returns a disconnected indicator:

{
  "tn": "7345551671",
  "disconnected": "yes"
}

Value	Meaning
yes	At least one disconnection event occurred after the provided reference date. The number may have been reassigned to a different subscriber.
no	No disconnection events were identified after the provided reference date.

Compliance Guidance

The recommended reference date is the date on which consent was obtained or the subscriber relationship was established. A response of "disconnected":"yes" indicates that the telephone number experienced a disconnection event after that date and should be treated as a potential reassigned number. Organizations should obtain updated consent or perform additional verification before initiating communications to the number.