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

# Add Payment Mandate

> Allow customers to add or update a payment mandate for future recurring payments.

The **Add Payment Mandate** flow allows an existing customer to securely add or replace the payment mandate associated with a subscription. This is commonly used when the customer wants to change their payment mandate or when the existing payment mandate has expired or become invalid.

After the payment mandate is successfully authorized, future recurring payments are collected using the newly saved payment mandate.

***

## Common Use Cases

| Scenario                  | Illustration                                                                        |
| ------------------------- | ----------------------------------------------------------------------------------- |
| Expired card              | The customer replaces an expired credit or debit card.                              |
| New bank account          | The customer switches to a different bank account or UPI account.                   |
| Mandate expired           | The existing UPI AutoPay or card mandate has expired and needs to be re-authorized. |
| Payment failures          | The customer updates their payment mandate after recurring payment failures.        |
| Preferred payment mandate | The customer changes the preferred payment mandate for future billing.              |
| Compliance requirement    | The merchant requests re-authentication of the customer's payment mandate.          |

***

## Workflow

```mermaid theme={null}
flowchart TB

A[Merchant Initiates<br/>Add Payment Mandate]
--> B[Generate Billing Session]

B --> C[Hosted Checkout]

C --> D[Customer Selects<br/>Payment Mandate]

D --> E[Customer Completes<br/>Mandate Authorization]

E --> F{"Authorization Successful?"}

F -->|Yes| G[Payment Mandate Saved]

G --> H[Future Recurring Payments<br/>Use Updated Payment Mandate]

F -->|No| I[Authorization Failed]

I --> J[Customer Retries]
```

***

## How It Works

1. The merchant calls <a href="https://docs.transactbridge.com/#b7abc54b-bf8a-4569-8f65-46b613600d47"> Add Mandate </a> API and generates an **Add Payment Mandate** session.
2. Transact Bridge returns a **payURL**.
3. The customer is redirected to the hosted checkout.
4. The customer selects a payment mandate (for example, UPI AutoPay or Card).
5. The customer completes the mandate authorization.
6. Once authorization is successful, the payment mandate is securely stored.
7. All future recurring payments use the newly added payment mandate.

***

## State Transition

```mermaid theme={null}
stateDiagram-v2

[*] --> ACTIVE

ACTIVE --> ACTIVE : Add Payment Mandate

ACTIVE --> ACTIVE : Payment Mandate Updated
```

***

## Notes

* Adding a payment mandate does **not** change the subscription status.
* The subscription remains **ACTIVE** throughout the process.
* The customer must successfully complete the hosted checkout and mandate authorization.
* Future recurring invoices are collected using the updated payment mandate.
* If the authorization fails or is abandoned, the existing payment mandate remains unchanged.