{"id":856,"date":"2026-10-09T14:13:50","date_gmt":"2026-10-09T14:13:50","guid":{"rendered":"https:\/\/microtalk.co.uk\/blog\/?p=856"},"modified":"2026-10-09T14:13:50","modified_gmt":"2026-10-09T14:13:50","slug":"carriers-call-blocking-obligations-fcc-rules-and-per-call-penalties","status":"publish","type":"post","link":"https:\/\/microtalk.co.uk\/blog\/carriers-call-blocking-obligations-fcc-rules-and-per-call-penalties\/","title":{"rendered":"Carriers’ Call Blocking Obligations \u2014 FCC Rules and Per-Call Penalties"},"content":{"rendered":"

The New Rules<\/span> of Call<\/span> Blocking<\/span><\/h1>\n

For years, carriers<\/span> have been expected to block illegal robocalls. But “expected” is not the same as “required.” The FCC<\/span> has now closed that gap.<\/p>\n

In March 2025, the FCC<\/span> adopted new rules<\/span> requiring all domestic voice service providers to block call<\/span>s based on a reasonable do-not-originate (DNO) list. The effective date for this requirement was December 15, 2025.<\/p>\n

This is a significant expansion of carriers<\/span>‘ call<\/span> blocking<\/span> obligations<\/span>\u2014and<\/span> it comes with real consequences for non-compliance.<\/p>\n

What Is a Do-Not-Originate (DNO) List?<\/h2>\n

A DNO list is a database of phone numbers that should never originate call<\/span>s. If a call<\/span> appears to come from a number on the DNO list, it is almost certainly spoofed and<\/span> should be blocked.<\/p>\n

Examples of numbers on a DNO list:<\/p>\n

– Numbers that belong to government agencies<\/p>\n

– Numbers that belong to law enforcement<\/p>\n

– Numbers that belong to other carriers<\/span><\/p>\n

– Numbers that have been identified as frequently spoofed<\/p>\n

The FCC<\/span>‘s requirement: Carriers<\/span> must use a “reasonable” DNO list to block call<\/span>s. The FCC<\/span> does not mandate a specific list\u2014carriers<\/span> can choose their own\u2014but the list must be reasonable and<\/span> effectively implemented.<\/p>\n

Additional Call<\/span> Blocking<\/span> Requirements<\/h3>\n

The FCC<\/span>‘s new rules<\/span> go beyond DNO lists:<\/p>\n

SIP Return Codes: Carriers<\/span> must return Session Initiation Protocol (SIP) error codes when blocking<\/span> call<\/span>s, so that originating carriers<\/span> know their call<\/span>s are being blocked.<\/p>\n

Exclusive Blocking<\/span> Notification Code: The FCC<\/span> has designated an exclusive code to notify call<\/span>ers when their call<\/span>s are blocked, empowering them to address erroneous blocking<\/span>.<\/p>\n

All Providers in the Call<\/span> Path: The FCC<\/span>‘s rules<\/span> apply to all providers in the call<\/span> path, not just terminating carriers<\/span>. This means intermediate providers and<\/span> gateway providers also have blocking<\/span> obligations<\/span>.<\/p>\n

The Enforcement Reality<\/h4>\n

The FCC<\/span> is serious about call<\/span> blocking<\/span> enforcement. The Commission’s ever-increasing requirements build on a January 2025 Report and<\/span> Order that imposed new requirements and<\/span> fees for RMD filers.<\/p>\n

What happens if you don’t block?<\/p>\n

– Per-<\/span>Call<\/span><\/span> Penalties<\/span>: The FCC<\/span> has established per-<\/span>call<\/span><\/span> penalty standards for call<\/span> blocking<\/span> violations. Each failure to block can result in significant fines.<\/p>\n

– Operational Disruption: If you are not blocking<\/span> illegal traffic, the FCC<\/span> may require other carriers<\/span> to block all of your traffic.<\/p>\n

– RMD Removal: Severe call<\/span> blocking<\/span> failures could lead to removal from the RMD<\/a>.<\/p>\n

The Gateway Provider Obligations<\/span><\/h5>\n

Gateway providers\u2014carriers<\/span> that accept traffic from foreign originating providers\u2014have additional obligations<\/span>:<\/p>\n

Gateway providers must take “reasonable and<\/span> effective steps to ensure that any foreign originating provider or foreign intermediate provider from which it directly receives traffic is not using the gateway provider to carry or process a high volume of illegal traffic onto the U.S.”<\/p>\n

This means gateway providers must actively vet their foreign partners and<\/span> block traffic from partners that generate illegal call<\/span>s.<\/p>\n

How to Implement Effective Call<\/span> Blocking<\/span><\/pre>\n
Implementing compliant call<\/span> blocking<\/span> requires a systematic approach:<\/p>\n
Choose a Reasonable DNO List: Select a DNO list that is comprehensive and<\/span> regularly updated.<\/p>\n
Implement Blocking<\/span> Technology: Use technology to automatically block call<\/span>s from DNO numbers.<\/p>\n
Monitor Blocking<\/span> Effectiveness: Regularly review your blocking<\/span> to ensure you are catching illegal traffic without blocking<\/span> legitimate call<\/span>s.<\/p>\n
Respond to FCC<\/span> Inquiries<\/a>: If the FCC<\/span> contacts you about blocking<\/span>, respond promptly and<\/span> demonstrate your compliance.<\/p>\n
Document Everything: Keep records of your DNO list, blocking<\/span> decisions, and<\/span> any challenges to blocking<\/span>.<\/p>\n
The Bottom Line<\/pre>\n
Call<\/span> blocking<\/span> is no longer optional for U.S. carriers<\/span>. The FCC<\/span> has mandated it, and<\/span> enforcement is coming.<\/p>\n
The December 15, 2025 deadline has gone past. Carriers<\/span> that failed to implement reasonable DNO-based blocking<\/span> face per-<\/span>call<\/span><\/span> penalties<\/span>, operational disruption, and<\/span> potential RMD removal.<\/p>\n
At Microtalk<\/a>, we help carriers<\/span> implement compliant call<\/span> blocking<\/span> solutions that meet FCC<\/span> requirements and<\/span> protect your business from enforcement actions.<\/p>\n
Does your carrier business abide the December 2025 call<\/span> blocking<\/span> deadline?<\/p>\n"},"excerpt":{"rendered":"
The New Rules of Call Blocking For years, carriers have been expected to block illegal robocalls. But “expected” is not the same as “required.” The FCC has now closed that gap. In March 2025, the FCC adopted new rules requiring all domestic voice service providers to block calls based on a reasonable do-not-originate (DNO) list. […]<\/p>\n","protected":false},"author":6,"featured_media":857,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[319],"tags":[364,161,366,162,279,365,322,4,370,369,368,367,301],"class_list":["post-856","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fcc-compliance-for-usa-traffic","tag-call-blocking","tag-call-centre","tag-carrier-compliance","tag-contact-centre","tag-dno","tag-do-not-originate","tag-fcc-compliance","tag-microtalk","tag-robocall-mitigation","tag-telecom-compliance","tag-telecom-regulation","tag-voice-service-provider","tag-wholesale-voice"],"_links":{"self":[{"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/posts\/856","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=856"}],"version-history":[{"count":1,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/posts\/856\/revisions"}],"predecessor-version":[{"id":858,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/posts\/856\/revisions\/858"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/media\/857"}],"wp:attachment":[{"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=856"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=856"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/microtalk.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=856"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}