Business texting glossary.
The words you meet when a business starts texting customers in the US and Canada, in plain language. Each definition links to the guide that explains it in full, with sources.
35 terms. Updated October 16, 2026. Not legal advice.
10DLC
Also called 10-digit long code.
An ordinary 10-digit US phone number used by a business to send texts to people. Before a 10DLC number can text US mobiles, the business’s brand and campaign must be registered with The Campaign Registry by a texting provider and reviewed by the carriers. Unregistered business traffic on these numbers is blocked.
A2P messaging
Also called application-to-person.
Texts a business sends to people through software, such as reminders, follow-ups and alerts, as opposed to person-to-person texts between individuals. In the US, A2P texts go over registered numbers: 10DLC numbers with a registered brand and campaign, verified toll-free numbers, or short codes.
ARRET
The French opt-out keyword, treated the same as STOP. Canada’s short code rules make STOP and ARRET mandatory opt-out keywords and say ARRET “must return a French response.” Any business texting Canadians should stop texts at once on either word and confirm in the matching language.
Brand
In 10DLC, the business that sends the texts, as registered with The Campaign Registry: its legal name, tax ID, address, website and a named contact. In the registry’s words, “If you are a company wanting to use SMS to communicate with your customers, you are considered a ‘Brand’.”
Campaign
In 10DLC, the registered description of what a brand texts: the use case, how people opt in, sample messages and the opt-out and help wording. Carriers review it with the brand before the numbers can send. In texting software, “campaign” usually also means a set of texts you send to a list.
Campaign Service Provider
Also called CSP.
The texting provider that registers brands and their campaigns with The Campaign Registry on behalf of the businesses it serves. Because brands cannot register themselves, every 10DLC registration goes through a provider, which also connects the approved campaign to the business’s numbers.
Carrier filtering
The checks mobile carriers run on business texts before delivering them. Texts from unregistered numbers, texts that look like spam and texts that break carrier rules can be blocked or delayed, often without notice to the sender. Registration, consent and clear opt-outs keep a business on the right side of them.
CASL
Also called Canada’s Anti-Spam Legislation.
Canada’s law for commercial electronic messages, texts included. A commercial text needs the recipient’s express or implied consent, must identify the sender with contact details, and must include an unsubscribe that takes effect within 10 business days. Penalties reach $10 million per violation.
CASL text messages: consent and unsubscribe rules for Canada
Consent record
The proof that a person agreed to receive texts: who agreed, the number, when, where it was given (the form, page or call) and the exact wording they agreed to. US and Canadian rules put the burden of proof on the sender, so the record matters as much as the consent itself.
CTIA
The US wireless industry association. Its Messaging Principles and Best Practices (2023) set what carriers expect from business texting: consent for every text, clear opt-outs, honest identification and content limits. They are not law, but carriers enforce them by filtering, blocking or suspending numbers.
Do Not Call registry
Also called DNC.
The US national list of numbers whose owners do not want sales calls, which the rules apply to sales texts too. A business may not send sales texts to a listed number without permission or an established business relationship, which lasts 18 months after a transaction and three months after an inquiry.
Express consent
Under CASL, consent a person gives in answer to a clear request that states its purpose and who is asking, and on whose behalf if that is someone else. Canada’s regulator says express consent does not expire, although the person can withdraw it at any time by unsubscribing.
CASL text messages: consent and unsubscribe rules for Canada
GSM-7
The basic 7-bit character set for SMS: the letters A to Z, digits, common punctuation and some accented letters. A text written only in GSM-7 fits 160 characters in one segment. A few characters from its extension table, such as [ ] { } and €, count as two.
HELP
The keyword a person texts to ask who is writing and how to get support. Carrier guidance expects an answer with the business name and a way to reach it. Canada’s short code rules also list the French AIDE and INFO. The opt-out line usually mentions HELP alongside STOP.
Implied consent
Under CASL, consent that comes from an existing relationship instead of a request. A purchase or lease gives two years from the transaction; an inquiry or application gives six months. After that the business needs express consent to keep sending commercial texts.
CASL text messages: consent and unsubscribe rules for Canada
Long code
Any ordinary 10-digit phone number, as opposed to a 5 or 6 digit short code. When a business uses a long code to text people in the US, it is called a 10DLC number and needs a registered brand and campaign. Long codes are the most common numbers for business texting.
MMS
Also called Multimedia Messaging Service.
A message that carries media, such as an image, a short video or audio, alongside text. MMS is sent and priced differently from SMS, and not every phone or number type handles it the same way. Most business follow-ups and reminders use plain SMS.
Opt-out line
The sentence at the end of a business text that tells people how to stop, for example “Reply STOP to opt out, HELP for help.” It is part of the sample messages registered with the campaign. Textually adds the registered line to every text until the person replies.
Phone type check
Also called line type lookup.
A lookup that tells whether a number is a mobile, a landline or invalid before anyone texts it. Running it on a list before it goes into a sequence means texts go only to numbers that can take them, and the list stays clean for the next send.
Prior express consent
The consent US rules require for autodialed texts that are not marketing, such as reminders and account updates. It is lighter than the prior express written consent that marketing texts need, and carriers expect an opt-in for every text either way, so keep a record of how each person agreed.
Prior express written consent
The consent US rules require before a business sends marketing texts with an autodialer: a signed written agreement, which can be electronic, in which the person gives the number and agrees to receive those texts from that business. It must be in place before the first text and should be kept as a record.
Quiet hours
Also called texting hours.
The times a business may not send sales texts. US federal rules bar them before 8 a.m. or after 9 p.m. in the recipient’s local time. Florida, Oklahoma and Maryland end at 8 p.m., and Connecticut allows 9 a.m. to 8 p.m. Weekdays from 9 a.m. to 6 p.m. local time fit every rule we checked.
Reassigned Numbers Database
An FCC database of US numbers that were disconnected and may now belong to someone else. A business that checks a number against it before texting gets a safe harbor under the FCC’s rules if the number turns out to have changed hands. It helps when consent records are old.
Short code
A 5 or 6 digit number used for high-volume business texting. Short codes go through carrier “upfront vetting and ongoing auditing” (CTIA, 2023), and they take longer and cost more to get than 10DLC or toll-free numbers. Canada’s short code rules make STOP and ARRET mandatory opt-out keywords.
SMS
Also called text message, Short Message Service.
The standard text message: plain text, sent and billed in segments. One segment holds up to 160 characters from the basic GSM-7 set, or 70 if the text contains an emoji or another character outside it. Longer texts are split into parts, and each part is charged.
SMS segment
The unit a text message is sent and billed in. One segment holds up to 160 characters when every character comes from the basic GSM-7 set, or 70 when the text has an emoji, a curly quote or another character outside it. Longer texts split into parts of 153 or 67 characters, each one charged.
Snowshoeing
Spreading the same message across many numbers to slip under carrier spam filters. Carriers treat it as a violation and block it. Using several registered numbers is fine when each contact stays on one number; sending one blast across many numbers to dodge limits is not.
Sticky sender
Also called one number per lead.
Keeping each contact on the number that first texted them, when a business texts from several numbers. Every automated step and every manual reply then comes from that same number, so the person sees one conversation and always knows who is writing.
STOP
The standard opt-out keyword. In the US, a reply of stop, quit, end, revoke, opt out, cancel or unsubscribe revokes consent by itself, and other wording counts if a reasonable person would read it as “stop texting me.” It must be honoured within 10 business days, with at most one confirmation.
TCPA
Also called Telephone Consumer Protection Act.
The US federal law, with FCC rules at 47 CFR 64.1200, that governs calls and texts to phones. It requires consent for autodialed texts and written consent for autodialed marketing texts, bars sales texts to numbers on the Do Not Call list without permission, and limits sales texts to 8 a.m. to 9 p.m. local time.
Text sequence
Also called drip text campaign, SMS cadence.
A series of texts sent automatically over days, with waits between them and conditions that decide the next step. A good sequence stops for a person as soon as they reply, so a human can take over. Teams use them for lead follow-up, onboarding, renewals and reminders.
The Campaign Registry
Also called TCR.
The database the US carriers use for 10DLC. It describes 10DLC as “an A2P messaging channel in which Brands and Campaign Service Providers (CSPs) are verified.” Businesses cannot register with it directly: “direct registration with TCR is not available for Brands,” so a texting provider registers them.
Toll-free verification
The review a toll-free number (800, 888, 877 and similar) must pass before it can text US or Canadian mobiles. The business submits its details, what it texts, how people opt in and sample messages. It typically takes one to two weeks. Business texts to Canadian mobiles usually go through a verified toll-free number.
Unicode (UCS-2)
The encoding a text switches to when it contains any character outside GSM-7, such as an emoji or a curly quote pasted from a document. A Unicode text fits 70 characters in one segment, or 67 per part when split, so a single emoji can double what a text costs.
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