> For the complete documentation index, see [llms.txt](https://developer.9bits.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.9bits.net/messaging/a2p-sms/smpp/sending-messages.md).

# Sending Messages

For sending messages, submit\_sm and data\_sm can be used.

When the characters of a message exceed 160 in a single submission, 9bits will split the messages, billing them accordingly.

## Source address

TON (Type of Number) and NPI (Numbering Plan Indicator) are used to specify and interpret the type and format of phone numbers and addresses. TON specifies whether the source address is a phone number or an alphanumeric string. NPI indicates the numbering scheme or plan for the phone number.

| TON  | Value         | NPI  | Value   |
| ---- | ------------- | ---- | ------- |
| 0x00 | Unknown       | 0x00 | Unknown |
| 0x01 | International | 0x01 | MSISDN  |
| 0x02 | National      |      |         |
| 0x05 | Alphanumeric  |      |         |

The type of source address is defined by the source address TON and NPI parameters.

* Alphanumeric sender is limited to a maximum length of 11 characters.
* MSISDN sender maximum length is 13
* If the source address is alphanumeric, we recommend using TON = 0x05 and NPI = 0x00

## Destination Address

A 9bits destination address should always be sent as the CC + NDC + SN. This is also referred to as the “MSISDN” of a subscriber. For further information on the MSISDN format, see the [ITU-T specification E.164](https://www.itu.int/rec/T-REC-E.164/en).

| TON  | Value         | NPI  | Value  |
| ---- | ------------- | ---- | ------ |
| 0x01 | International | 0x01 | MSISDN |

The type of destination address is defined by the destination address TON and NPI parameters.

* Destination address is limited to a maximum length of 13 characters.
* If the source address is international, we recommend using TON = 0x01 and NPI = 0x01


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