---
title: "Add a payment method to a customer"
description: "Adds a reusable payment method to an existing customer."
type: "mcp_operation"
company: "RevCent"
operation_id: "AddCustomerPaymentMethod"
canonical: "https://revcent.com/documentation/markdown/mcp/operation/AddCustomerPaymentMethod.md"
api_schema: "https://revcent.com/documentation/files/api/operation/AddCustomerPaymentMethod.json"
---

# RevCent MCP Guide: `AddCustomerPaymentMethod`

Adds a reusable payment method to an existing customer. Card payment methods are currently supported.

## Operation

- API: `POST /v2/customers/{customer_id}/payment_methods`
- Required permission: `customer:add_payment_method`.
- Available profiles: MCP and AI Voice Agents.
- Related overview: [OverviewCustomerPaymentMethod](https://revcent.com/documentation/markdown/mcp/operation/OverviewCustomerPaymentMethod.md).

## Inputs

| Parameter | Location | Required | Meaning |
|---|---|---|---|
| `customer_id` | URL path | Yes | The customer that owns the payment method. IDs contain 20 characters. |

MCP arguments include these identifiers. In a direct HTTP request, substitute them into the URL; do not duplicate them in the JSON body.

The JSON body requires `payment_method`. It accepts these fields:

| Field | Requirement | Meaning |
|---|---|---|
| `payment_method.method` | Required; `card` | The method being added. |
| `payment_method.card.card_number` | Required string | Complete card number; spaces or hyphens may separate digits. Length: 12–23 characters. |
| `payment_method.card.exp_month` | Required integer | Expiration month, 1–12. |
| `payment_method.card.exp_year` | Required integer | Two-digit or four-digit expiration year. |
| `payment_method.card.card_code` | Optional string | Three or four numeric digits. |
| `bill_to` | Optional object | Billing details; existing customer information is used if omitted. |
| `set_as_default` | Optional boolean; defaults to `false` | Make this the customer's default card. The first card becomes the default. |

`bill_to` accepts `first_name`, `last_name`, `email`, `phone`, `company`, `address_line_1`, `address_line_2`, `city`, `state`, `zip`, and `country`. Use a three-letter ISO 3166-1 alpha-3 country code, such as `USA` or `CAN`.

This operation adds cards only. The broader categories returned by the retrieval operations do not add wallet or bank-account inputs to this request. Adding a method does not create a sale or process its payment.

## MCP argument example

```json
{
  "customer_id": "CCCCCCCCCCCCCCCCCCCC",
  "payment_method": {
    "method": "card",
    "card": {
      "card_number": "4242424242424242",
      "exp_month": 12,
      "exp_year": 2030
    }
  },
  "set_as_default": true
}
```

IDs are illustrative. Substitute IDs returned by the customer and payment-method operations. The card number is synthetic example data; use the intended card details for a real request.

## Result and next step

A successful response can include `customer_id`, `payment_method_id`, `result`, and API response metadata. Card responses may also include the public `customer_card_id`; use `payment_method_id` for the Customer Payment Method routes. These responses do not contain full card credentials.

Use the returned `payment_method_id` to retrieve the method or explicitly select it in a supported sale request. Adding a card and setting it as default are distinct from processing a payment.

[GetCustomerPaymentMethods](https://revcent.com/documentation/markdown/mcp/operation/GetCustomerPaymentMethods.md) lists the customer's methods. [OverviewCustomerPaymentMethod](https://revcent.com/documentation/markdown/mcp/operation/OverviewCustomerPaymentMethod.md) explains categories, defaults, and saved-method selection.

API errors can include `code: 0`, `error_code`, `message`, and `result`. Use the response to determine whether the action completed; do not treat an error as a successful change.


---
Document Parent Directory
* [Operations](https://revcent.com/documentation/markdown/mcp/operation/index.md) - AI/MCP details and overviews for operations available within the RevCent MCP.