SMS Message Size & Character Limits

How Many Characters Fit in One SMS?

It depends on the encoding your message needs. Plain Latin text fits far more into a single SMS than Chinese, Arabic or Japanese, because non-Latin scripts need a wider character set. iSMS detects the encoding automatically as you type, and the live counter tells you how many credits the message will use before you send.

Longer Messages: How Credits Are Counted

A message longer than one SMS is joined and arrives on the handset as a single message, but it is billed per part. The first part carries the full allowance; each additional part carries slightly less, because some of it is used to stitch the message back together.

Credit Boundaries at a Glance

Your Brand Name Counts Toward the Limit

If your account has a brand name configured, it is added to the start of every message and counts toward the total. A nine-character brand name leaves 144 characters of the first ASCII SMS for your own text. The counter on the Compose SMS page shows message length, brand length and total separately, so the figure you see is the figure you are billed on.

Supported Characters

• Letters a–z A–Z and digits 0–9
• Common punctuation: ! @ # $ % & * ( ) - _ + = ; : " ' < > , . ? /
• Any Unicode script — Chinese, Japanese, Korean, Arabic, Tamil, Cyrillic, Greek — using Unicode encoding
• Separate multiple recipients with a semicolon ;

Before You Send

Two things worth knowing about billing. Credits are charged once a message is submitted to the telco, so an Undelivered status does not refund the credit — but a message rejected outright at the SMSC returns a Fail status and is not charged. See SMS Delivery Reports for what each status means. And delivery time varies with gateway traffic, particularly around festive periods, so schedule campaigns with some headroom.