SMS Marketing Character Limits: Best Practices for 2026

SMS marketing has the highest open rate of any channel — often cited above 90% — but that only holds if your message respects the 160-character constraint that makes texts feel personal rather than like an ad. Here's how to write SMS marketing copy that performs.

Why SMS Marketing Copy Should Stay Under 160 Characters

Unlike email, where a longer subject line just gets truncated, an SMS marketing message that spills into a second segment is often visibly delivered as two separate texts on the recipient's phone. That breaks the "personal text from a friend" feel that makes SMS marketing effective in the first place. Staying within a single 160-character GSM-7 segment keeps your message reading as one coherent text.

Anatomy of a High-Converting SMS Marketing Message

For the complete interactive reference with all fields for every platform, visit our all-platforms character limit cheat sheet — with 16 platforms in one page and links to dedicated tools for each.

The Compliance Tax on Your Character Budget

In the US, TCPA compliance typically requires an opt-out instruction ("Reply STOP to unsubscribe") on marketing texts, which eats roughly 25-30 characters out of your 160-character budget before you've written a word of actual copy. Many SMS platforms append this automatically — check whether your platform's character counter includes it before you finalize copy length.

Copywriting Rules for 160 Characters

• Lead with the offer, not the brand name — recipients already know who's texting them from the sender ID
• Use one call to action, one link — SMS isn't the channel for multiple options
• Avoid emoji unless your brand voice depends on it; each one risks tripling your segment cost
• Personalization tokens like [First Name] should be tested at their longest plausible value, not their placeholder length
• Time-sensitive language ("today only", "ends at midnight") performs consistently well within the space constraint

Timing and Frequency Alongside Length

Character limits aren't the only lever — SMS marketing best practice generally recommends 2-4 messages per month maximum to avoid opt-outs, with each message doing more work per character than an equivalent email would need to.

For the underlying mechanics of how limits work, see our SMS character limit guide and segment billing breakdown. If you're pairing SMS with email marketing, our meta description SEO guide and Google Ads copy tips cover similarly tight-constraint copywriting. Amazon sellers running post-purchase SMS flows may find our Amazon listing optimization guide useful for consistent messaging.