TCR Error Code 9106: How to Fix Missing Opt-Out Language in Your 10DLC A2P Campaign

If you’ve submitted a 10DLC A2P campaign and received Error Code 9106, you’re not alone. It’s one of the most common rejection codes issued by The Campaign Registry (TCR), and the good news is that it’s entirely fixable once you understand exactly what triggered it and what carriers expect to see. This guide walks you through the root causes of Error 9106, the exact language you need to include, step-by-step remediation instructions, and best practices to prevent the same rejection from happening again on your next submission.

What Is TCR Error Code 9106?

TCR Error Code 9106 is a campaign rejection flag indicating that your sample messages are missing required opt-out language. Specifically, it means that the message samples you submitted during 10DLC campaign registration do not include clear instructions telling recipients how to stop receiving messages — most commonly the absence of a “Reply STOP to opt out” instruction or an equivalent compliant phrase.

This is not a minor formatting issue. Opt-out language is a foundational requirement under both TCPA regulations and the carrier code of conduct enforced by T-Mobile, AT&T, Verizon, and the broader CTIA messaging guidelines. When TCR reviewers evaluate your campaign samples, the presence of clear opt-out instructions is one of the first things they check. Missing it will result in an automatic rejection regardless of how well the rest of your campaign registration is configured.

Why Carriers Require Opt-Out Language in Every SMS Campaign

Before diving into the fix, it’s worth understanding why this requirement exists — because understanding the “why” helps you implement it correctly and avoid repeat rejections.

Mobile carriers have a direct financial and reputational stake in the quality of A2P messaging traffic that flows over their networks. When consumers receive unwanted text messages with no way to stop them, complaint rates rise, trust in the messaging channel erodes, and carriers absorb the cost of that degraded experience. Mandatory opt-out instructions protect consumers by ensuring they always have a clear, simple path to unsubscribe from any commercial messaging program.

The CTIA’s messaging guidelines — which carriers use as their compliance baseline — require that every A2P messaging program provide recipients with the ability to opt out by texting STOP, and that this option be clearly communicated to subscribers. TCR enforces this at the campaign registration level by requiring that opt-out language appear in your sample messages before your campaign is approved.

T-Mobile in particular has historically been the strictest of the major carriers when it comes to opt-out compliance, and their review standards heavily influence what TCR flags during the registration review process. If your samples don’t include clear opt-out instructions, T-Mobile’s requirements alone would block your campaign from proceeding — even if AT&T and Verizon might have passed it.

Root Causes of Error 9106

Error 9106 can be triggered by several specific issues, all related to how opt-out language is — or isn’t — present in your submitted message samples. The most common root causes include:

No STOP keyword in any sample message. This is the most straightforward trigger. If none of your submitted message samples contain the word STOP with an instruction to use it for opting out, you will receive Error 9106. Every campaign must include at least one sample message that explicitly tells the recipient how to stop messages.

Incomplete opt-out phrasing. Including the word “STOP” alone isn’t always sufficient. TCR reviewers look for a complete opt-out instruction that makes the action clear to the consumer. A message that says “STOP” in passing — without framing it as an unsubscribe instruction — may still trigger a rejection. The phrasing needs to unambiguously communicate that replying STOP will end the messages.

Missing HELP keyword. Many Error 9106 rejections also flag the absence of a HELP keyword instruction alongside the STOP instruction. Best practice — and the standard expected by carriers — is to include both: “Reply STOP to unsubscribe, HELP for help.” Omitting the HELP keyword from your opt-out disclosure is a common oversight that contributes to 9106 rejections.

Opt-out language buried or absent from the initial message. If your campaign involves a multi-message flow, opt-out instructions must appear in the first message a subscriber receives — not just in a later follow-up. Reviewers evaluate whether the consumer would have been informed of their opt-out rights from the start of the messaging relationship.

Vague or non-standard phrasing. Using custom opt-out language that doesn’t include the STOP keyword — such as “reply CANCEL to end” or “text QUIT to unsubscribe” — may also trigger a rejection, particularly if the primary STOP keyword isn’t also present. While some carriers recognize additional keywords like QUIT, CANCEL, END, and UNSUBSCRIBE, STOP must always be included as the primary opt-out keyword.

Step-by-Step Fix for Error 9106

Remediating Error 9106 is straightforward once you know what to add. Here’s a step-by-step process to update your campaign samples and resubmit successfully.

Step 1: Review all submitted sample messages. Log into your TCR-connected platform or CSP portal and pull up the sample messages you submitted with the rejected campaign. Read through each one and identify whether any of them contain a STOP opt-out instruction. If none do, that’s your primary fix.

Step 2: Add compliant opt-out language to at least one sample — ideally all of them. Your opt-out disclosure should appear in at least one sample message, but the safest approach is to include it in every sample. This eliminates any ambiguity about whether your campaign meets the requirement and demonstrates to reviewers that opt-out compliance is built into your messaging flow, not bolted on.

Step 3: Use approved opt-out phrasing. The following phrases are widely accepted as compliant by TCR and carriers:

• “Reply STOP to unsubscribe.”
• “Text STOP to opt out.”
• “Reply STOP to end messages. Reply HELP for help.”
• “Txt STOP to cancel. Msg&Data rates may apply.”

Pair your STOP instruction with a HELP instruction in the same disclosure line. This combined format — “Reply STOP to unsubscribe, HELP for help” — is the industry standard and the format that reviewers expect to see.

Step 4: Verify your message templates match your samples. One of the most common causes of repeat rejections is a mismatch between the sample messages submitted to TCR and the actual message templates used in your sending platform. After updating your samples, make sure your live message templates are updated to match. If your templates don’t include the opt-out language that your samples show, you risk compliance violations even after your campaign is approved.

Step 5: Check keyword consistency across your flow. Make sure that the STOP keyword you’re advertising in your messages is actually configured in your platform as a recognized opt-out keyword. If a subscriber texts STOP and your system doesn’t honor it immediately, you’ve created a compliance liability even if your sample messages pass review. Confirm that your messaging platform processes STOP (and ideally QUIT, CANCEL, END, and UNSUBSCRIBE) as immediate opt-out triggers.

Step 6: Resubmit your campaign. Once your samples have been updated with compliant opt-out language and your templates are aligned, resubmit your campaign through your CSP. If your campaign was suspended rather than fully rejected, some platforms allow you to edit and resubmit without creating a new campaign — check with your provider on the correct resubmission process.

Best Practices for Opt-Out Phrasing

Getting the specific language right matters. Here are the formatting and content guidelines that produce the highest first-pass approval rates:

Always use STOP as the primary keyword. Regardless of what other keywords your platform supports, STOP must be present. It is the universally recognized opt-out keyword across all major U.S. carriers and the one that TCR reviewers are specifically looking for.

Keep the opt-out disclosure concise and at the end of the message. The standard placement is a brief disclosure line appended to the end of the message body: “Msg&Data rates may apply. Reply STOP to unsubscribe, HELP for help.” This format is clean, compliant, and familiar to reviewers.

Include message frequency if your campaign sends recurring messages. For subscription-style campaigns, include a frequency disclosure alongside your opt-out language: “Msg freq varies. Msg&Data rates may apply. Reply STOP to cancel, HELP for info.” This additional disclosure reduces complaint rates and reflects the full set of disclosures that CTIA guidelines recommend.

Don’t truncate the opt-out disclosure in sample messages. Sometimes senders abbreviate their sample messages for convenience, cutting the opt-out footer in the process. Your samples should reflect exactly what a recipient would receive — opt-out disclosure included.

Prevention: How to Avoid Error 9106 on Future Submissions

Once you’ve resolved a 9106 rejection, the goal is to never see it again. A few simple practices will keep your future submissions clean:

Use a pre-submission checklist. Before submitting any 10DLC campaign, run your sample messages through a quick checklist: Does at least one sample include STOP? Does it include HELP? Is the phrasing complete and unambiguous? Does it match what your live templates actually send?

Build opt-out language into your message template library. Rather than adding opt-out disclosures manually to each campaign, build them into your standard template footers. Every template in your library should include the STOP/HELP disclosure by default, making compliance automatic rather than optional.

Audit your samples against carrier-specific standards. T-Mobile, AT&T, and Verizon each publish messaging guidelines that align with CTIA standards. Reviewing your samples against these guidelines before submission — rather than after rejection — saves significant time and protects your campaign throughput.

Test your opt-out flow before submitting. Send your messages to a test number and actually reply STOP. Confirm that your platform honors the opt-out immediately, logs it correctly, and stops sending. A functioning opt-out mechanism isn’t just a TCR requirement — it’s a TCPA compliance obligation.

First-Pass Approvals and Trust Scores

Every campaign rejection creates friction: resubmission delays, potential interruptions to live messaging programs, and incremental damage to your sender reputation with carriers. First-pass approval isn’t just convenient — it’s a meaningful factor in building and maintaining the high trust scores that protect your deliverability over time.

Carriers evaluate your A2P messaging program holistically. A track record of clean campaign registrations, compliant message templates, and low complaint rates contributes positively to your trust score. Repeated rejections and resubmissions, by contrast, signal to carriers that your compliance practices may be inconsistent — which can affect how your traffic is treated even after your campaign is approved.

Fixing Error 9106 correctly the first time, and building opt-out compliance into your standard workflow going forward, is one of the simplest and highest-impact steps you can take to protect your program’s long-term standing.

More 10DLC Guidance from mytcrplus.com

TCR Error Code 9106 is just one of the many rejection codes that can slow down your 10DLC campaign registration process. Subscribe to the mytcrplus.com YouTube channel for ongoing breakdowns of TCR error codes, 10DLC registration tips, A2P compliance best practices, and carrier update alerts — everything you need to register faster, stay compliant, and keep your SMS program running without interruption.

If you’re managing multiple campaigns or building out a new messaging program, getting your opt-out language right from the start isn’t just about passing TCR review — it’s about building a program that carriers, regulators, and your subscribers can trust.