Why are affiliates the soft target in TCPA litigation?
Because the affiliate collected the phone number, wrote the consent language, and holds the consent record, so when a buyer gets a demand letter, the first question is where the lead came from. Picture it: you drove 4,000 leads for a home warranty advertiser last quarter, got paid per lead, and moved on. Six months later one of those leads turns out to be a serial TCPA plaintiff. The advertiser’s legal team is handling its own exposure, and if your lead agreement has an indemnity clause, some of that exposure is now yours. The advertiser has in-house counsel and insurance. You may have neither.
Statutory damages under the TCPA are $500 per violation, up to $1,500 if the violation is willful or knowing (47 U.S.C. § 227(b)(3)). A modest lead campaign touching 50,000 numbers with a 1% problem rate is 500 numbers, which puts $250,000 to $750,000 on the table for every call or text, before a class is certified. You don’t need to lose at trial for that number to end your business.
What happened to the FCC’s multi-buyer consent rule?
It was struck down before it took effect. A common affiliate practice was to write consent language broad enough to cover dozens of buyers: one form submission, one consent disclosure, many callers. In its December 2023 order (FCC 23-107), the FCC called this the “lead generator loophole” and required consent to be given to one seller at a time. That rule was due to apply from January 27, 2025, but on January 24, 2025 the Eleventh Circuit vacated it in Insurance Marketing Coalition v. FCC. The rest of the order, including Do Not Call protections for text messages, still stands.
So one-to-one consent is not a federal requirement. That doesn’t make blanket partner language safe. Prior express written consent still has to be a signed agreement that clearly authorizes the seller to send telemarketing calls or texts to that number (47 CFR 64.1200(f)(9)). A generic “and partners” disclosure gives each buyer weak evidence that this consumer agreed to hear from them. Selling the same lead 8 or 10 times means that consent has to hold up 8 or 10 times.
For a detailed breakdown of what consent language holds up, see our article on prior express written consent under the TCPA.
The five fields that form your minimum defensive layer
Validation doesn’t make bad consent good. What it does is keep you from compounding a consent problem with a delivery problem, and it filters out the numbers most likely to generate complaints or litigation before you ever transmit them. Here are the five fields I’d treat as non-negotiable.
litigator
This is the one I would never skip. The litigator field, returned when you pass litigatorFilter: true in your request to POST https://api.checkthatphone.com/v1/lookup, is "true" when the number matches our TCPA litigator database, which is refreshed daily. The response also includes litigator_type ("litigator", "plaintiff" or "agitator") and, when one is on record, litigator_name, so you know what you’re looking at.
Professional plaintiffs are a real category: people who file TCPA suits repeatedly, and who have every reason to fill in lead forms. The litigator scrub is the most direct technical control for catching them before you transmit the lead to a buyer. Cost of a lookup with the scrub: two credits, about a cent or less. Cost of missing one: see the statutory damages math above.
The ROI math of running a litigator filter on every send works through the numbers, and the TCPA litigator scrub use case shows the integration.
blackList
blackList is "true" when the number is on our internal blacklist of flagged numbers, or when the litigator filter matched (a litigator hit forces this flag). Check reason and litigator to see which one triggered it. Either way the number is one to keep out of your buyer feed.
You also get reason, action, and in some cases deactivationDate alongside it, which tell you why a number is flagged and what the recommended handling is. If you also want complaint history, the free dncComplainer check flags numbers on our national list of people who have complained about telemarketers but haven’t sued.
deliverable
A number that isn’t in service can’t consent to anything, and calling a number that has been reassigned to someone new can be a violation even if the previous owner consented. deliverable is "false" whenever action is "unsubscribe": a litigator match, a non-mobile or non-SMS-capable line, a blacklist hit, or a carrier deactivation in the last 45 days. deactivationDate tells you when that deactivation happened.
Neither field detects reassignment. A number that was deactivated and then reactivated shows no deactivationDate, whether it went back to the same person or to someone new. For consented numbers you plan to keep calling, the FCC’s Reassigned Numbers Database is the tool built for that question.
If you sell leads for SMS and deliverable comes back "false", drop the lead. For voice-only buyers, read reason first: a landline fails SMS deliverability but may be perfectly callable.
nanpType
This field returns the line type from numbering-plan data: "mobile", "landline", or "not-mobile". It matters for TCPA because the strictest autodialer and prerecorded-voice rules apply to mobile numbers, and landlines get different treatment. Getting this wrong in either direction is expensive: miss a mobile classification and you’ve applied weaker scrutiny to a high-risk number; misclassify a mobile as a landline and you’ve sent an autodialed text you may not have consent for.
Numbering-plan data doesn’t follow a number when it ports, so check nanpType against dipCarrierType, which comes from a live carrier dip at lookup time and reflects the current carrier. When they disagree, trust dipCarrierType. The line type also gates your landline SMS logic: if your campaigns include text-enabled landlines (via landlineSmsLookup: true), you need the base line type first.
dipCarrierSubType
This is the field most affiliates skip. dipCarrierSubType classifies the current carrier from the live carrier dip: WIRELESS or PCS for mobile carriers, ILEC, CLEC or RBOC for landline carriers, IPES for VoIP, WRSL for wireless resellers (MVNOs), and a few others. Why does this matter for TCPA?
First, VoIP numbers are cheap to obtain in bulk, which is why many lead buyers treat them as higher risk. Second, some buyers won’t accept certain carrier subtypes at all, and if you transmit a lead they reject on those grounds, you’ve done the work for nothing.
Knowing the subtype before transmission lets you route accordingly or reject early.
How to run this in practice
For real-time lead validation, call POST https://api.checkthatphone.com/v1/lookup with your Authorization: Bearer <key> header and include litigatorFilter: true in the request body. You get all five fields back in a single synchronous response, so you can run it inline on a lead form submission before you write the record to your CRM. The affiliate and lead-gen use case shows where the call sits in a typical flow.
For existing lists, especially a lead pool you’re about to re-engage, use the Bulk CSV uploader in the CheckThatPhone dashboard. Upload your number list, turn on the add-ons you want (the litigator scrub, landline SMS lookup), and download the result file. We deduplicate automatically, and the upload and result file are hard-deleted within 24 hours. With the litigator scrub on, each lookup uses 2 credits, so 50,000 numbers is 100,000 credits: $100 if it fits in the 100K plan’s monthly allowance, or $300 on the 10K plan with overage. Check /pricing for current rates.
See /use-cases/contact-list-hygiene for a walkthrough of the bulk flow.
The numbers that make this math obvious
One willful TCPA violation can cost up to $1,500 per contact. One lookup with the litigator scrub costs 2 credits, roughly $0.002 to $0.01 depending on your plan. That’s a ratio of at least 150,000 to 1 in favor of running the filter. It is hard to find a better return on a compliance spend.
Validating deliverability and line type alone isn’t enough. Those checks tell you whether a number can be reached, not whether the person behind it sues. The litigator scrub is the piece that answers the second question.
If you’re transmitting leads to buyers who contact consumers by phone or SMS, validate before you send. Five fields, one API call, one lookup per lead. If you’re on the selling side, how lead buyers score affiliate phone leads shows what buyers check. The documentation is at /docs.