SMS marketing software glossary and key terms
The jargon of SMS marketing, from 10DLC and A2P to segments, opt in and deliverability, defined in plain language and in the context that matters to a buyer.
SMS marketing carries a thicket of jargon, much of it about US carrier rules and billing rather than the texts themselves. This glossary defines the terms you will meet while shopping for and running a platform, in plain language and in the context that matters to a buyer.
For how these terms play out in price, see the pricing and cost guide; for rollout, the implementation guide; and for the ranked tools, our best SMS marketing software hub.
The tool reviews linked below carry affiliate links marked rel="sponsored"; we may earn a commission. Our rankings are editorial and are never for sale. See our disclosure.
SMS marketing terms, defined
10 digit long code, the standard US number type for application to person business texting. Carriers require you to register a brand and campaign on a 10DLC number before they will reliably deliver marketing messages.
Application to person messaging, where software sends texts to people, as opposed to person to person. US A2P traffic must be registered and is subject to carrier rules and fees.
A single unit of an SMS, up to 160 characters of plain text. Longer messages split into multiple segments, and you are billed per segment, so message length affects cost.
The billing unit on flat plan tools. A 160 character SMS usually costs one credit and an MMS three; some plans roll unused credits over and some let them expire.
Multimedia messaging service, a text with an image, GIF or longer body. MMS costs more than SMS, commonly about three times as much, so image heavy campaigns need separate budgeting.
The consent a subscriber gives to receive your texts. US marketing requires express written consent, and you should record when and how each opt in happened.
A two step opt in where the subscriber confirms by replying or clicking after the first sign up. It produces a cleaner, more engaged list at the cost of some sign up drop off.
A subscriber unsubscribing, usually by replying with a keyword such as STOP. Platforms must honor opt outs immediately and confirm them automatically.
The Telephone Consumer Protection Act, the main US law governing marketing texts. It underpins consent, opt out and timing rules; treat platform compliance features as help meeting it, not legal advice.
Times of day when marketing messages should not be sent, based on the recipient's local time. Respecting quiet hours is both good practice and part of staying compliant.
A 5 or 6 digit number built for high volume A2P texting and two way keywords. Short codes offer high throughput and strong deliverability but cost more and take longer to provision than a long code.
A toll free number used for A2P texting. It supports higher volume than an unregistered long code and must be verified with carriers before sending at scale.
A word subscribers text to your number to opt in or trigger an action, such as texting JOIN to subscribe. Keywords power list growth and simple two way flows.
A shortened, often branded link used in texts to save characters and to track clicks. Carriers can filter generic public shorteners, so a branded shortlink helps deliverability and attribution.
A message or series triggered by an event, such as a welcome, an abandoned cart, or an order update. Automations do steady work between campaigns and often drive most of a program's revenue.
A one time message sent to a segment of your list, such as a promotion or launch. Broadcasts drive spikes, while automations drive the baseline.
A setup where subscribers can reply and you can respond, usually through a shared inbox with routing and saved replies. Essential for support and sales, unnecessary for broadcast only programs.
The share of your messages that actually reach handsets. It depends on registration, list quality, content and carrier filtering, and is the single biggest driver of whether a program works.
The screening US carriers apply to A2P traffic, which can block or throttle messages with risky links, restricted content, or from unregistered numbers. Registration and clean content reduce filtering.
How many messages a number can send per second. Short codes offer the highest throughput, which matters when you send to a large list in a tight window.
How you credit revenue to SMS, for example via tracked links or a holdout group. Loose attribution flatters your ROI by crediting sales that would have happened anyway, so measure against a baseline.
Per message surcharges US carriers add on top of the platform rate, generally a fraction of a cent each. Some tools include them in the price and some pass them through as a separate line.
How pricing terms show up across tools
Pricing as of June 2026; check each vendor for current pricing. Scores are editorial assessments against our SMS marketing rubric, not vendor claims.
Go deeper
10DLC stands for 10 digit long code, the standard US number type for application to person business texting. Carriers require you to register a brand and a campaign on a 10DLC number before they will reliably deliver marketing messages, and small registration and monthly campaign fees apply.
SMS is a plain text message of up to 160 characters per segment, while MMS carries an image, GIF or longer body. MMS costs more, commonly about three times an SMS or three credits on flat plans, so image heavy campaigns need separate budgeting. Verified June 2026; check the vendor for current pricing.
Opt in is the consent a subscriber gives to receive your texts. US marketing requires express written consent, and you should record when and how each opt in happened. A double opt in adds a confirmation step for a cleaner, more engaged list.
US carriers screen A2P traffic and can block or throttle messages from unregistered numbers, with risky or generic shortened links, or with restricted content. Registering a 10DLC brand and campaign, using a branded shortlink, keeping a consented list and avoiding flagged content all reduce carrier filtering.
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