> ## Documentation Index
> Fetch the complete documentation index at: https://docs.airdun.com/llms.txt
> Use this file to discover all available pages before exploring further.

# SMS Recovery: Deterministic Text Reminders

> How the SMS recovery channel works in Airdun: a provisioned number, fixed deterministic copy with no voices, and where SMS fits in a recovery sequence.

SMS is a short, direct recovery channel. The strategy algorithm reaches for it when a customer's engagement signals suggest a more immediate touch than email — or as an escalation step later in a sequence.

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## No voices — fixed copy

Unlike email, SMS is **voiceless**: it sends deterministic, fixed messages rather than model-written copy in a chosen voice. There is nothing to configure per message. Every SMS still carries the single Stripe link the customer uses to update their card and settle the balance.

<Note>
  Because SMS copy is fixed, there are no voices to set up for it. Voices apply to [Email](/configuration/voices) only.
</Note>

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## The number

Airdun provisions a phone number on your behalf — local where available. There is nothing to buy or configure on your end.

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## Timing and language

Like every channel, SMS is timed to the customer's local working hours, and the message is sent in the customer's detected language. When SMS is used, and in what order relative to other channels, is decided per case — see [Recovery Strategy](/how-it-works/recovery-strategy).

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## Enabling SMS

Toggle SMS on from the **Channels** page in your dashboard. See [Channels Setup](/configuration/channels-setup) for the full procedure, and [Channels](/features/channels) for how the channel order is decided per case.