US wireless carriers actively filter and block text messages they think are spam or that break the rules for business texting. When that happens, your messages quietly fail to deliver, or your number gets flagged and stops sending altogether. Recovery is slow, so it is worth understanding what triggers a block before it happens.
This article explains how filtering works, which kinds of content commonly cause problems, the formatting and link mistakes to avoid, and what to do instead.
A few terms
A2P: application-to-person messaging. Texts sent from software (like Raise More) to a person, as opposed to one person texting another from their phone.
10DLC: the registration system US carriers require for A2P texting over standard 10-digit local numbers. Your campaign registration tells the carriers who you are and what you send.
Opt-out: a recipient's request to stop receiving your texts, usually by replying STOP. Honoring opt-outs is legally required.
How carrier filtering decides
Carriers and their spam-detection partners score every message before it reaches a phone. They look at the sending number's reputation, whether the content matches the use case you registered under 10DLC, the words and links in the message, how many identical messages you send at once, and how many recipients report your texts as spam. A message that looks unsolicited, deceptive, or like a prohibited category gets filtered. Too many filtered messages, or a spike in spam complaints, can get the number itself blocked.
Two things matter most. First, your actual messages have to match the 10DLC use case your number is registered under. If your registration describes political fundraising but you send something that reads like a payday loan offer, the mismatch raises flags. Raise More handles 10DLC registration with you during onboarding, so if you are unsure what your number is registered for, contact support before changing the kind of content you send. Second, you have to be texting people who agreed to hear from you.
Content that commonly triggers blocks
Carriers treat certain categories as high-risk. The industry shorthand is SHAFT: Sex, Hate, Alcohol, Firearms, and Tobacco. Cannabis, gambling, and high-risk financial offers (loans, debt relief, payday lending, crypto) are also heavily restricted or outright prohibited for A2P texting.
For political fundraising specifically, the categories that cause trouble are usually not the SHAFT list directly, but content that pattern-matches to spam:
High-risk financial language: phrases like "guaranteed match," "act now to claim," "you've been selected," or anything that reads like a prize, loan, or get-rich offer.
Misleading or alarmist claims: fake deadlines, false statements about the recipient's account or donation status, or impersonation of another organization.
Prohibited or flagged words: profanity, hate speech, and explicit content. Some spam filters also flag clusters of urgency words.
Even legitimate fundraising appeals can get filtered if the wording leans heavily on urgency and reward framing, because that is exactly what spam campaigns do.
Formatting and link pitfalls
The way a message is written matters as much as the topic:
Public URL shorteners like bit.ly, tinyurl, and similar shared domains are a common block trigger. Carriers cannot see where a shared short link points, so they treat it as suspicious. Use your campaign's own domain or a branded link instead.
ALL CAPS and excessive punctuation ("DONATE NOW!!!") reads as spam to filters.
No sender identification. If a recipient cannot tell who is texting, the message looks deceptive. Name your campaign or organization clearly.
No opt-out language. Messages without a way to stop are both a filtering risk and a compliance problem.
Identical high-volume blasts. Sending the exact same message to a large list in a short window looks automated and spammy.
What to do instead
Keep your real messages consistent with the 10DLC use case your number is registered under. Raise More sets this up with you during onboarding; if the content you send is changing, check with support first.
Only text people who opted in. Sending to purchased or scraped lists, or to people who never agreed to hear from you, drives spam complaints fast.
Identify yourself. Open with your campaign or organization name.
Include opt-out instructions, typically "Reply STOP to unsubscribe." Raise More handles opt-outs automatically: when a contact replies with a stop word (STOP, END, CANCEL, QUIT, UNSUB, REMOVE, and similar) at the start of their text, that phone number is marked removed for texting and is skipped on future SMS campaigns.
Use your own link domain, not a public shortener.
Write like a person, not a billboard. Skip the all-caps and the exclamation pile-ups, and avoid prize or guaranteed-reward framing.
FAQ
My messages send but never seem to arrive. Is my number blocked?
Often this is carrier filtering rather than a full block. The send succeeds on your end but the carrier drops the message before delivery. Check that your content matches your registered use case and does not trip the patterns above.
Do I have to include "Reply STOP" on every message?
Including opt-out language regularly is best practice and reduces filtering. At minimum it must be clear how recipients can opt out. Raise More processes the opt-out itself: a reply that starts with a stop word (STOP, END, CANCEL, QUIT, and similar) suppresses that number from future sends, so you do not have to remove opted-out contacts by hand.
Can one bad message get my whole number blocked?
A single message usually causes a filter, not a block. Repeated filtered messages or a spike in spam complaints is what gets a number flagged or blocked, and that is hard to reverse.
Is political content itself prohibited?
No. Political fundraising is a permitted A2P use case when registered correctly. The risk comes from spammy wording, bad links, or texting people who did not opt in, not from the political topic.