Reference · primary sources

Official US Government Resources

The authoritative .gov sources behind every rule on this site — the FCC, FTC, the US Code, the CFR, and more. When a vendor doc and a government source disagree, the government source wins.

reference Last verified mid-2026 2 min read

This page collects the primary government sources for US A2P texting and calling. Industry and vendor documentation (Twilio, Telnyx, TCR, CTIA, etc.) is useful for how-to, but it is secondary. For what the law actually requires, go to the source.

Why primary sources matter
Fees, deadlines, and rules on third-party sites — including this one — can lag the official record. Before you rely on a number or a rule for a compliance decision, confirm it against the relevant .gov source below and, where it matters, a qualified attorney.

Federal Communications Commission (FCC)

The FCC enforces the TCPA , mandates STIR/SHAKEN caller-ID authentication, and operates the RMD .

ResourceWhat it coversOfficial link
FCC — homeThe regulator for US telecomhttps://www.fcc.gov/
Telemarketing & robocallsConsumer-facing TCPA / robocall ruleshttps://www.fcc.gov/general/telemarketing-and-robocalls
Call authentication (STIR/SHAKEN)Caller-ID authentication framework & mandateshttps://www.fcc.gov/call-authentication
Robocall Mitigation DatabaseWhere voice providers certify mitigationhttps://www.fcc.gov/robocall-mitigation-database
Stop unwanted robocalls & textsOfficial consumer guidancehttps://www.fcc.gov/consumers/guides/stop-unwanted-robocalls-and-texts
FCC consumer complaint centerWhere consumers report violationshttps://consumercomplaints.fcc.gov/

Federal Trade Commission (FTC)

The FTC enforces the Telemarketing Sales Rule (TSR), runs the National Do Not Call Registry, and publishes business compliance guidance (including CAN-SPAM).

ResourceWhat it coversOfficial link
FTC — business guidanceCompliance guidance for businesseshttps://www.ftc.gov/business-guidance
Telemarketing Sales RuleThe TSR (16 CFR Part 310)https://www.ftc.gov/legal-library/browse/rules/telemarketing-sales-rule
National Do Not Call RegistryRegister / verify / report (consumers & sellers)https://www.donotcall.gov/
Complying with the Telemarketing Sales RulePlain-language FTC compliance guidehttps://www.ftc.gov/business-guidance/resources/complying-telemarketing-sales-rule

Statutes & regulations (the actual law)

AuthorityCitationOfficial link
Telephone Consumer Protection Act47 U.S.C. § 227https://uscode.house.gov/view.xhtml?req=(title:47%20section:227)
TCPA implementing rules47 CFR § 64.1200https://www.ecfr.gov/current/title-47/chapter-I/subchapter-B/part-64/subpart-L/section-64.1200
Electronic Code of Federal RegulationseCFR (browse all current rules)https://www.ecfr.gov/
Federal RegisterProposed & final rulemakings, comment docketshttps://www.federalregister.gov/agencies/federal-communications-commission
TRACED Act (2019)Pallone–Thune TRACED Act, S.151https://www.congress.gov/bill/116th-congress/senate-bill/151

Other official resources

ResourceWhat it coversOfficial link
IRS — Apply for an EINThe Employer Identification Number you register withhttps://www.irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-number-ein-online
IRS — Tax Exempt Organization SearchVerify 501(c)(3) status for charity messaginghttps://www.irs.gov/charities-non-profits/tax-exempt-organization-search
USTelecom — Industry Traceback GroupFCC-designated traceback consortium under the TRACED Acthttps://ustelecom.org/industry-traceback-group/
Government URLs change too
Agencies reorganize their sites. If a link 404s, search the agency’s domain (e.g. site:fcc.gov call authentication) rather than trusting a cached third-party copy.

Looking for the dated history of what changed? See the regulatory change tracker.