SMS is the only marketing channel where a mistake is instant, billed, and legally actionable.

Consent is stricter than you expect

Consent for email does not transfer to SMS. Consent for transactional messages, like a delivery notification, does not cover marketing. Someone giving you a phone number to receive a booking confirmation has not agreed to receive an offer, and treating those as the same thing is the most common serious mistake in this channel.

In the United States the relevant law carries statutory damages per message, which means a single mis-sent campaign to a few thousand people is a genuinely dangerous number rather than an embarrassment. Other jurisdictions vary, but none of them are more relaxed than email.

So the software question is whether the tool records what each person consented to and when, and whether it can stop you sending marketing to a number that only ever agreed to transactional messages. A tool that treats every stored number as mailable is not protecting you.

• Does it record the consent source and timestamp per number?
• Does it distinguish transactional consent from marketing consent?
• Can it block a send to numbers without marketing consent?
• Is there a written record you could produce in a dispute?
• Does it handle different rules by country?

Opt-out must be automatic and instant

STOP is not a courtesy. In most jurisdictions, and under the carrier rules that sit on top of the law, a recipient who replies STOP must be removed immediately and permanently, and the same applies to a handful of variants like UNSUBSCRIBE, CANCEL, END and QUIT.

This has to be handled by the platform, automatically, before any human sees it. If a vendor tells you opt-outs appear in an inbox for someone to action, that is a compliance failure waiting for a busy week, and it is one of the clearest reasons to end a sales conversation.

Check the suppression list too. Once a number opts out it must stay suppressed across every campaign and every sequence, permanently, including one someone builds next year having forgotten this conversation.

Work out the real cost per message

SMS is billed per segment, not per message, and a segment is 160 characters of plain GSM text or 70 characters once any character forces the message into unicode. The characters that force that switch are ordinary ones: curly quotes, em dashes, most emoji, accented letters. A message that looks like one text can be billed as three.

The specific trap is a tool that shows you a character count without showing you the segment count, because those are different numbers and only one of them is on your bill. Paste your real message in and confirm the tool tells you what it will cost before sending.

Then multiply by your list size and be honest about whether the channel earns that. SMS costs meaningfully more per recipient than email, so it should be reserved for messages that justify the interruption rather than used as another broadcast channel.

• 160 characters per segment in plain GSM encoding
• 70 characters per segment once unicode is triggered
• Curly quotes and emoji trigger unicode
• Long messages are split and billed per part
• International rates differ substantially by destination

Insist on delivery receipts

Accepted by the carrier and delivered to the handset are different events, and the gap between them is where numbers that no longer exist, phones that are off and carrier blocks all live. A tool reporting only sends is reporting the least interesting of the three.

Ask to see per-message delivery status and what the failure reasons look like. If everything is aggregated into a single percentage, you cannot clean your list, because you cannot tell which numbers failed.

This matters more over time than it seems on day one. Phone numbers churn faster than email addresses, and a list you never clean quietly becomes a list you are paying to send into nothing.

Where Creaiter stands on SMS

Creaiter sends SMS with automatic STOP and opt-out handling, a permanent suppression list, delivery receipts, and accurate segment counting so the cost you are shown before sending is the cost you are billed. Those are the things this guide argues you should insist on, and they are why they were built first.

What it does not have is the telecoms depth of a dedicated SMS platform: short code provisioning, carrier-level throughput management, two-way conversational inboxes with agent assignment, or MMS. If SMS is your primary channel rather than one of several, a specialist will serve you better.

The case for Creaiter here is that the text is written in the same voice, from the same content, as everything else you send, and that the consent record is shared with your email list rather than kept somewhere separate.