For e-commerce text programs and agencies
Check each number when it opts in and re-scrub the list before campaigns: whether it can take a text, whether a carrier deactivated it in the last 45 days, whether it belongs to a known TCPA litigator, and its local time for quiet hours.
| Number | The lookup says | Do this |
|---|---|---|
| (415) 555-0123 | Mobile, can take texts | Send |
| (718) 555-0161 | Landline that can take texts | Send |
| (312) 555-0105 | Landline, can't take texts | Drop |
| (480) 555-0177 | Deactivated by the carrier Oct 3 | Remove |
| (305) 555-0138 | Known TCPA litigator | Suppress |
Fictional 555 numbers.
About 32% of the numbers we look up are landline or VoIP, and most landlines can't take a text. action and smsEligible tell you which numbers can.
Source: CheckThatPhone lookup data
actionnanpTypesmsEligible The wireless industry's messaging guidelines say senders should process deactivation files regularly (for example, daily) and remove deactivated numbers from opt-in lists.
CTIA Messaging Principles 5.1.5 · api.ctia.org
deactivationDatereason About 1.5% of the numbers we check come back flagged as TCPA litigators when the scrub is on.
Source: CheckThatPhone lookup data
litigatorlitigator_type No telephone solicitations before 8 a.m. or after 9 p.m., local time at the called party's location, and the rule covers marketing texts to cell phones too.
47 CFR 64.1200(c)(1), (e) · ecfr.gov
timezonetzOffset One API call from checkout or the signup popup, before the confirmation text goes out. Add landlineSmsLookup to catch landlines that can take texts.
Deactivation entries expire after 45 days, so re-check the active list at least monthly. CSV upload takes up to 1,000,000 rows.
Run the send list with the litigator scrub (+1 credit per number) before it goes to your SMS platform.
Read these fields from every response. Absent DNC fields mean the check didn't run, not that the number is clear.
| If the response shows | Field | Do this |
|---|---|---|
| Can take a text | action = sendsmsEligible | Send. |
| Not a mobile number | reason = Not a valid mobile numbernanpType | Run the landline SMS check (+1 credit per landline), or drop it. |
| Deactivated by the carrier recently | deactivationDatereason | Remove it from the opt-in list, as the CTIA guidelines recommend. |
| Known TCPA litigator | litigator | Suppress. |
| On our internal blacklist | blackList | Suppress. A litigator match also sets it; reason tells you which. |
| State DNC or complainer match | dncStateResult = STATE DNCdncComplainerResult = DNC COMPLAINER | Your logic decides: a match never changes action. Absent fields mean not checked, never clear. |
| Local time | timezonetzOffset | Schedule sends between 8 a.m. and 9 p.m. at the recipient's location. Without an IP, this is the area code's zone. |
A mobile that can take a text and is on a state do-not-call list. action stays "send" because the DNC checks never change it: whether to suppress it is your call, based on your consent records.
Highlighted fields: action, litigator, dncStateResult, timezone, smsEligible.
{
"success": true,
"credits_used": 2,
"data": {
"subscriber": "4045550129",
"optDate": "2026-10-09T16:05:33.104Z",
"action": "send",
"deliverable": "true",
"nanpType": "mobile",
"blackList": "false",
"dip": "success",
"dipLrn": "4045550129",
"dipPorted": "false",
"dipOcn": "6010",
"dipCarrierSubType": "WIRELESS",
"dipCarrier": "AT&T",
"dipCarrierType": "mobile",
"litigator": "false",
"litigator_type": "",
"litigator_name": "",
"dncStateChecked": "true",
"dncStateResult": "STATE DNC",
"dncComplainerChecked": "true",
"dncComplainerResult": "",
"dncOtherChecked": "true",
"geoState": "GA",
"geoCity": "atlanta",
"geoCountry": "US",
"timezone": "America/New_York",
"tzOffset": 5,
"geoSource": "area-code",
"error": "false",
"smsEligible": "true"
}
}Monthly cost, with the TCPA litigator scrub (+1 credit per number):
State DNC and complainer checks never add credits. The landline SMS check adds 1 credit per landline; mobiles are not charged.
Not legal advice.
dncStateChecked is left out for them, so "not checked" never reads as clear.deactivationDate: data refreshed daily, with a 1 to 7 day lag, and entries expire after 45 days. It is not a reassigned-number check.No. 10DLC brands and campaigns are registered with The Campaign Registry, and brands can't register directly: your messaging provider handles it. The lookup doesn't register, vet or approve anything.
Some of them. About 7% of the landlines we check are SMS-capable. Add landlineSmsLookup to find them: 1 extra credit per landline, and mobiles aren't charged. A landline that can take a text comes back with smsEligible: "true".
Partly. deactivationDate flags a number a carrier deactivated in the last 45 days, from data refreshed daily with a 1 to 7 day lag. Once a number is reactivated the date clears, whether it went back to the same subscriber or a new one, so it isn't reassigned-number detection. The FCC's Reassigned Numbers Database is built for that.
No. The state DNC and complainer checks are informational: a match never changes action. Decide in your own logic, based on your consent records. Absent DNC fields mean the check didn't run, not that the number is clear.
Don't text that number. reason says why, and it is one of four strings: "Associated with TCPA Litigator DO NOT CONTACT", "Not a valid mobile number", "Blacklisted Subscriber", or "Number deactivated by carrier id <N> on <date>".
No. Replies go to your messaging platform, not to us. Opt-outs can come by any reasonable method and must be honored within 10 business days (47 CFR 64.1200(a)(10)). blackList is our internal blacklist, not your opt-out list.
500 free lookups a month. Call the API at opt-in, or upload the list as a CSV.