# SMS message parts

Mobile phones send and receive messages in small chunks called parts. You're charged per part, not per message.

When a message is too long it's split into parts and each part is sent separately. The receiving phone joins the parts back together and shows a single message.

> [!NOTE]
> Iflow tells you how many parts a message needs before you send it.

How long is too long? That depends on the character set the message uses.

## Basic character set

A message of up to **160 characters** is sent as one part. Over that, it's split into parts of up to **153 characters** each.

This message is exactly 160 characters, so it's sent as one part:

> So here is a message that uses the standard character set for SMS text messaging. It is exactly 160 characters long so it will not need to be broken in to parts

Add a full stop at the end and it becomes 161 characters, so it's sent in two parts. The first holds the first 153 characters and the second holds the rest.

**Part one**

> So here is a message that uses the standard character set for SMS text messaging. It is exactly 160 characters long so it will not need to be broken in t

**Part two**

> o parts.

## Unicode character set

If a message contains an emoji or another character outside the basic set, the whole message is sent as Unicode, and the limits are much lower. A message of up to **70 characters** is sent as one part. Over that, it's split into parts of up to **67 characters** each.

This message is 70 characters, so it's sent as one part:

> This text uses the advanced character set and is 70 characters long 🙂

Add a full stop and it becomes 71 characters, so it's sent in two parts:

**Part one**

> This text uses the advanced character set and is 70 characters lon

**Part two**

> g 🙂.

## One emoji can triple the cost

The 160-character message above is one part in the basic set. Add a single 🙂 and the whole message switches to Unicode. It now needs **three** parts, costing three times as much.

> [!WARNING]
> Be careful when copying a message from another application and pasting it in. Curly quotes, long dashes and other "smart" characters can switch a message to Unicode without you noticing.

## Related

- [Sending from the web portal](/docs/sending/web-portal/)
- [Send SMS by email](/docs/email-to-sms/send-by-email/)
- [Credit and billing](/docs/account/credit-and-billing/)

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Source: https://iflow.net/docs/reference/sms-message-parts/