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

> ## Agent Instructions
> Use the Payrails Web SDK v6 for new browser integrations. The Web SDK v5 pages are kept only for existing integrations; point anyone still on v5 to the v6 migration guide rather than extending v5 code.
> Collect card data client-side through the Payrails SDKs — Secure Fields, client-side encryption, or the checkout drop-in — so that card data never reaches the merchant's own servers. Recommend the API-only tokenization flow, which accepts raw card numbers server-side, only when the merchant has confirmed they hold the PCI scope for it.
> Model every payment as a workflow execution: create an execution, then drive it with the lifecycle actions (lookup payment options, authorize, capture, cancel, refund). Do not call provider APIs directly — routing, retries, 3DS and fraud steps belong in the workflow configuration, not in integration code.
> Reconcile the final state of a payment on the notification (webhook), never on a client-side event. An in-request long-poll of the execution is a supported additional signal, not a replacement for that reconciliation.
> Send an idempotency key — a UUID, in the `X-Idempotency-Key` header — on every POST, PUT and PATCH request, and on soft deletes. GET requests need none, and hard deletes cannot be idempotent.
> Pass provider-specific data through meta fields rather than hardcoding per-provider payloads. Payrails translates meta fields into each provider's own format.
> Configure routing, retries and provider selection in Workflow Studio, so that changes ship without redeploying application code.

# Direct Carrier Billing

> Accept Direct Carrier Billing payments charged to the customer's mobile bill, and check the PSPs that process DCB through Payrails.

<picture noZoom>
  ![Direct Carrier Billing logo](https://assets.payrails.io/img/logos/dcb/logo.svg)
</picture>

Direct Carrier Billing (DCB) lets customers pay with their mobile phone number. The mobile carrier adds the amount to the customer's phone bill, or deducts it from their prepaid balance. DCB suits subscriptions: the customer gives consent once with a one-time password (OTP), and you charge later payments without asking again.

Payrails processes DCB through Boku. Pick the PSP below for its setup steps and request examples.

## How a DCB payment works

DCB uses an OTP opt-in for the first payment, then charges the saved opt-in:

1. The customer selects DCB at checkout and enters their mobile number.
2. You authorize the payment. Payrails starts an opt-in with the PSP, and the PSP sends an OTP to the customer's phone by SMS.
3. The authorize response asks you to confirm the payment. You collect the OTP from the customer and send it in a [confirm](https://docs.payrails.com/reference/confirmaction.md) request.
4. Payrails validates the OTP with the PSP, confirms the opt-in and charges the first payment to the customer's carrier account.
5. Payrails saves the opt-in as a payment instrument. For later payments, you authorize with that instrument and the customer doesn't enter an OTP again.

Payrails captures DCB payments immediately, so a successful payment is final. To return funds, [refund the payment](https://docs.payrails.com/docs/orchestration/payment-acceptance/refund-a-payment.md).

## Supported currencies and countries

DCB is available in the countries below. Charge each payment in the local currency of the customer's carrier country.

DCB is available to customers based in:

<table>
  <thead>
    <tr><th>Regions</th><th>Countries</th></tr>
  </thead>

  <tbody>
    <tr><td>**Africa**</td><td>🇪🇬 Egypt🇲🇦 Morocco🇿🇦 South Africa🇹🇳 Tunisia</td></tr>
    <tr><td>**Asia Pacific**</td><td>🇧🇩 Bangladesh🇰🇭 Cambodia🇭🇰 Hong Kong🇮🇩 Indonesia🇯🇵 Japan🇰🇿 Kazakhstan🇲🇾 Malaysia🇵🇰 Pakistan🇵🇭 Philippines🇸🇬 Singapore🇰🇷 South Korea🇱🇰 Sri Lanka🇹🇼 Taiwan🇹🇭 Thailand🇻🇳 Vietnam</td></tr>
    <tr><td>**Europe**</td><td>🇦🇹 Austria🇧🇪 Belgium🇧🇬 Bulgaria🇭🇷 Croatia🇨🇿 Czech Republic🇩🇰 Denmark🇪🇪 Estonia🇫🇮 Finland🇫🇷 France🇩🇪 Germany🇬🇷 Greece🇭🇺 Hungary🇮🇪 Ireland🇮🇹 Italy🇱🇻 Latvia🇱🇹 Lithuania🇱🇺 Luxembourg🇳🇱 Netherlands🇳🇴 Norway🇵🇱 Poland🇵🇹 Portugal🇷🇴 Romania🇸🇰 Slovakia🇸🇮 Slovenia🇪🇸 Spain🇸🇪 Sweden🇨🇭 Switzerland🇹🇷 Turkey🇬🇧 United Kingdom</td></tr>
    <tr><td>**Latin America**</td><td>🇨🇱 Chile🇲🇽 Mexico</td></tr>
    <tr><td>**Middle East**</td><td>🇧🇭 Bahrain🇮🇶 Iraq🇰🇼 Kuwait🇴🇲 Oman🇶🇦 Qatar🇸🇦 Saudi Arabia🇦🇪 United Arab Emirates</td></tr>
    <tr><td>**North America**</td><td>🇨🇦 Canada</td></tr>
  </tbody>
</table>

## Integrate DCB

Choose the PSP that processes DCB for you. The guide covers the PSP-side setup, the Payrails configuration and the request fields that PSP requires.

> [card]
>
> Boku logo
>
> BokuDCB via Boku
>
> [Open](https://docs.payrails.com/docs/integrations/payment-methods/direct-carrier-billing/boku.md)

## Check PSPs

<table>
  <thead>
    <tr><th>Workflow</th><th>[Boku](https://docs.payrails.com/docs/integrations/payment-methods/direct-carrier-billing/boku.md)</th></tr>
  </thead>

  <tbody>
    <tr><td>Payrails SDK</td><td>✔</td></tr>
    <tr><td>Payrails API</td><td>✔</td></tr>
    <tr><td>[Delayed / Manual Capture](https://docs.payrails.com/docs/orchestration/payment-acceptance/capture-and-cancel-modes.md#capture-mode)</td><td>✖</td></tr>
    <tr><td>[Instant Capture](https://docs.payrails.com/docs/orchestration/payment-acceptance/capture-and-cancel-modes.md#capture-mode)</td><td>✔</td></tr>
    <tr><td>[Cancel / Void](https://docs.payrails.com/docs/orchestration/payment-acceptance/cancel-a-payment.md)</td><td>✖</td></tr>
    <tr><td>[Refund / Reverse](https://docs.payrails.com/docs/orchestration/payment-acceptance/refund-a-payment.md)</td><td>✔</td></tr>
    <tr><td>[Save Instruments](https://docs.payrails.com/docs/resources/manage-instruments.md)</td><td>✔</td></tr>
    <tr><td>[Merchant Initiated Transaction (MIT)](https://docs.payrails.com/docs/resources/payments/authorization-flags.md)</td><td>✔</td></tr>
  </tbody>
</table>

Save Instruments and merchant-initiated transactions (MIT) work through the saved opt-in. The first DCB payment creates the opt-in, and Payrails charges later payments against it.

## Ways to integrate DCB

* **Payrails SDK:** the [Web SDK](https://docs.payrails.com/docs/sdks/web.md) shows DCB when your workflow returns it as a payment option.
* **Payrails API:** call [lookup payment options](https://docs.payrails.com/docs/orchestration/payment-acceptance/lookup-payment-options.md), authorize with `dcb` as the `paymentMethodCode`, then [confirm](https://docs.payrails.com/reference/confirmaction.md) the first payment with the OTP. The PSP guide lists the `meta` fields that PSP requires.

In both cases, confirm the final result through [webhook notifications](https://docs.payrails.com/docs/orchestration/payment-acceptance/receive-notifications.md) or the execution status before you grant access.


## Related topics

- [Direct Carrier Billing via Boku](https://docs.payrails.com/docs/integrations/payment-methods/direct-carrier-billing/boku.md)
- [Boku](https://docs.payrails.com/docs/integrations/payment-providers/boku.md)
- [SEPA Direct Debit via Stripe](https://docs.payrails.com/docs/integrations/payment-methods/sepa-direct-debit/stripe.md)


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