Your appointment reminders went out Tuesday morning the same way they have for two years. The software says sent. The customer says nothing arrived. There is no bounce, no error code, no warning banner - just a no-show at 9 AM and a confused front desk. If this is happening to you right now, it is almost certainly not a glitch. It is a carrier rule called A2P 10DLC, and since early 2025 it has been silently discarding messages from businesses that never registered.
The name is pure telecom jargon (Application-to-Person, 10-Digit Long Code), but the fix is not complicated. This is the plain-English version: what changed, what registration actually costs, how long it really takes, and the exact mistakes that get applications rejected.
The blocking started in February 2025
For years, US carriers treated unregistered business texting as a tolerated gray zone. Messages from unregistered local numbers were throttled, surcharged, or occasionally filtered, but most still got through - which is why plenty of small businesses never knew the rules existed.
That grace period is over. Since February 2025, major US carriers block messages from unregistered 10DLC numbers outright. Not slowed down, not partially filtered - blocked. And the failure is quiet: your platform can show the message as sent because the carrier accepted it before discarding it. From your side, everything looks normal. From your customer's side, you simply went silent.
If software sent it, it counts as A2P
The most common misunderstanding is that these rules only apply to mass marketing blasts. They do not. A2P covers any text sent through software: a scheduling platform, a CRM, a field service app, a review-request tool. The carriers do not care about your intent or your volume - they care about the route. If a message traveled from an application to a person, it is A2P, and the number that sent it must be registered.
Three parties, one registry
Every registration runs through the same chain: your business gives its information to your software platform, and your platform files it with The Campaign Registry (TCR), the central database all major US carriers check before delivering a message. You cannot register with TCR directly - it only accepts filings from registered providers. The whole process happens inside whatever software you use to text, usually on a settings page called something like Messaging Compliance or A2P Registration.
- Brand registration - who you are. Your legal business name exactly as the IRS has it, your EIN, address, and website. Approval typically clears in days, often through an automated EIN check.
- Campaign registration - what you send. A declared use case (appointment reminders, customer care, marketing), two to five sample messages, and a description of how customers opt in. This is the step where rejections happen.
- Number assignment. Your phone numbers get linked to the approved campaign. From that point, carriers deliver your traffic instead of discarding it.
What it costs and how long it takes
The fees are real but small. Brand registration is a one-time charge of roughly $4 to $20, depending on your platform's markup. Each campaign then carries a recurring fee of about $15 to $30 per month. Some platforms absorb these costs; most pass them through on your bill. Either way, this is not the expensive part - the expensive part is the month of dropped reminders while you are unregistered.
On timing: brand approval usually clears within days. Campaign approval takes 3 to 7 business days, because most filings route through a secondary human review. Budget one to three weeks end to end, and start well before the season when you can least afford missed reminders. Every rejection adds another full review cycle to that clock.
The four rejections that eat your timeline
Campaign reviews fail for a short list of predictable reasons. Four of them account for most of the pain:
- The use case and the samples do not match. You declared 'customer care' but your sample messages read like promotions - '20% off duct cleaning this week!'. The reviewer sees marketing filed as service traffic and rejects. Your samples must look exactly like the messages your declared use case describes.
- No opt-in or opt-out language in the samples. Reviewers want at least one sample that names your business and includes opt-out wording such as 'Reply STOP to opt out.' Samples that read like anonymous fragments get flagged.
- The EIN does not match the IRS legal name. If your EIN belongs to 'Summit Home Services LLC' but you register the brand as 'Summit Plumbing', automated verification fails. Use the exact legal name from your IRS paperwork (the CP 575 letter), and put the trade name in the DBA field.
- Marketing and reminders mixed in one campaign. An appointment-reminder campaign whose samples include a promotional blast reads as misdeclared traffic. Register them separately - reminders under customer care or account notifications, promotions under marketing - or declare a mixed use case and accept heavier scrutiny.
Fixing a rejection is usually a wording problem, not a business problem. But each resubmission restarts a 3-7 business day clock, which is how a 'quick registration' quietly turns into a lost month.
Opt-in you can prove
Campaign registration asks how customers consent to your texts, and carriers can audit that claim later. 'They gave us their number' is not consent. What holds up is documentation:
- Form language at the point of collection. Next to every phone field, wording like: 'By providing your phone number, you agree to receive appointment reminders and service updates from [Business Name]. Message and data rates may apply. Reply STOP to unsubscribe.'
- A separate, unchecked-by-default checkbox for marketing. Consent to reminders is not consent to promotions, and a pre-checked box is not consent to anything.
- Records you can produce on request. Keep screenshots of your forms exactly as they appeared, export checkbox records with timestamps, and note verbal opt-ins on the customer record with a date. When a carrier or auditor asks, being able to show the evidence is what settles it.
One caution: consent rules also intersect with the TCPA, which carries statutory penalties per message. Treat this article as operational guidance, not legal advice, and run your opt-in language past your attorney - especially for marketing texts.
Start the clock today
If your texts are failing right now, the path is short: open the compliance page in your texting platform today and check your registration status. Pull your IRS EIN letter and confirm the legal name matches what you plan to file. Write sample messages that mirror what you actually send, with your business name and STOP language included. Then file, and keep reminders and marketing in separate campaigns.
Done cleanly, you are one to three weeks away from reliable delivery. Done sloppily, you are a month of silent no-shows away from the exact same place.
Frequently asked questions
The most likely cause is A2P 10DLC enforcement: since February 2025, major US carriers block messages from unregistered local business numbers outright. The failure is silent, so your software may still show messages as sent. Check your registration status in your texting platform before troubleshooting anything else.
Expect a one-time brand registration fee of roughly $4 to $20 and a recurring campaign fee of about $15 to $30 per month, billed through your texting platform. There is no way to pay The Campaign Registry directly - all fees flow through your software provider, sometimes with a small markup.
Brand approval usually clears within days, and campaign approval takes 3 to 7 business days because most filings get a human review. Plan on one to three weeks end to end, and remember that every rejection restarts the campaign review clock.
Yes, if those texts go through any software - a CRM, a scheduling tool, a field service app. Carriers classify messages by route, not volume, so a hand-typed one-to-one reply sent through a platform is still A2P. Only texts sent from a phone's native messaging app count as person-to-person.