# Message Campaign Parameters

When you bulk-load contacts into a message campaign from a comma-separated values (CSV) file, each column must follow the rules described below. Use this reference to prepare your file before uploading it.

## Parameters

| Parameter | Description | Required | Rules | Default |
| --- | --- | --- | --- | --- |
| Number | The destination phone number for the message campaign. | Yes | Digits only, and the value must begin with a `+`. Use the format `+{Number}`, for example, `+12025550101`. The whole value, including the leading `+`, can be at most 16 characters long. | N/A |

:::tip
Enter each number as one unbroken string of digits after the `+`, with no spaces, dashes, or parentheses. The `+` is followed by the country code (for example, `1` for the US and Canada), so `+1 (202) 555-0101` should be written as `+12025550101`.
:::

:::note
The `Number` column is mandatory. A row without a valid number in the required `+{Number}` format will not import.
:::