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This page covers how messages and addresses must be formatted before sending them to the Messaging Platform.

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Encoding types

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GSM 7-bit (IA5 / GSM 03.38)

SMS text messages are usually encoded using the GSM 7-bit default character set (GSM 03.38 / IA5). The platform applies standard GSM encoding rules for most Latin-script messages.

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UCS2

When sending messages that require UCS2 (Unicode), each SMS part can contain a maximum of 70 characters. Longer messages are split into multiple parts automatically. Use UCS2 when your content includes characters not supported by the GSM 7-bit alphabet.

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Binary

Set CHARCODE=2 and provide message content in hex format (for example 0x41 0x42 0x43). Binary messages can include a User Data Header (UDH) for WAP Push and similar services.
Encoding is applied at the SMSC/platform level, not per account. The destination SMSC or mobile network operator (MNO) may also determine how messages are encoded for delivery.By default, the platform uses standard GSM 7-bit encoding rules. Contact your account manager if you need guidance on encoding for a specific destination country.

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URL encoding

All requests must be properly URL encoded as per RFC 1738. Since URLs can only include a limited set of characters (A–Z, a–z, 0–9, $-_.+!*'(),), all other characters must be escaped. Most programming languages provide utility classes for URL encoding, including Java, Perl, PHP, and .NET.
Source and destination addresses must never include a leading + character. In a URL, + represents an escaped space — not a plus sign.

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Addresses

Source and destination addresses (senders and recipients) are usually numeric international GSM numbers starting with the country code, without leading zeros or plus signs. Example destination: 255650000001 It is also possible to use alphanumeric source addresses, which can be a maximum of 11 characters in the GSM network. For best results, use only characters A–Z, a–z, 0–9, and spaces. Use SOURCEADDRTON to specify the type of number for the source address:

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User Data Header (UDH)

Binary messages can include a User Data Header for features such as WAP Push. Set UDHI to a non-zero value when UDH is present in the message body, and provide the UDH bytes in the UDH parameter. Example WAP Push UDH: 0x06 0x05 0x04 0x0b 0x84 0x23 0xf0