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

# Retailer selection

> A single hosted URL where customers choose which retailer to connect.

## Overview

Each [Link URL](/docs/subtotal-link/link-urls) launches Subtotal Link for one specific retailer. The **retailer-selection URL** is a hosted page that shows customers every retailer your program supports — under your brand's name and icon — and lets them choose which account to connect.

Picking a retailer starts the standard Subtotal Link flow for that retailer. Nothing else about the linking experience changes: the customer sees the same consent and login screens, and lands on your `redirect_url` after a successful connection.

## URL format

```
https://link.subtotal.com/select
  ?client_id=01KFCQK5H2M4R8W3T7Y9NBVCXZ
  &customer_id=8a46e581-48ba-498a-9ad0-2ee72582e1af
  &redirect_url=https%3A%2F%2Fexample.com%2Fprofile
```

## Query parameters

| Parameter      | Required | Description                                                                                                                                                                 | Example                                |
| :------------- | :------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :------------------------------------- |
| `client_id`    | Yes      | Identifies your brand and determines the branding and retailers shown. Provided by Subtotal — reach out to your Subtotal contact if you don't have it.                      | `01KFCQK5H2M4R8W3T7Y9NBVCXZ`           |
| `customer_id`  | No       | A unique identifier used to map connections to customer records across external systems. Behaves exactly as on [Link URLs](/docs/subtotal-link/link-urls#query-parameters). | `8a46e581-48ba-498a-9ad0-2ee72582e1af` |
| `redirect_url` | No       | The URL that customers should be redirected to after successfully linking their account. Behaves exactly as on [Link URLs](/docs/subtotal-link/link-urls#query-parameters). | `https://example.com/profile`          |

<Note>
  URL-encode the `redirect_url` value — especially when it carries query parameters of its own.
</Note>

Any other Link URL query parameters you include (for example `email` and `mobile`) are passed through unchanged to the chosen retailer's Link flow.

## What your customers see

The page lists the retailers configured for your program, each as an identical option. When a customer picks one:

1. The standard Subtotal Link flow for that retailer begins — consent, then the retailer login.
2. If the `customer_id` you passed already has a connection for that retailer, it is reused automatically instead of creating a duplicate — picking an already-connected retailer simply re-links it.
3. After a successful connection, the customer is redirected to your `redirect_url` (or shown the standard success screen if you didn't provide one).

The page never displays connection status — every retailer looks the same regardless of whether the customer has linked it before.

## When to use it

| Use…                           | When…                                                                                                                                       |
| :----------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------ |
| A per-retailer **Link URL**    | The surface targets one retailer — for example, a "Connect your Walmart account" campaign.                                                  |
| The **retailer-selection URL** | The customer decides which retailer to connect — loyalty hubs, profile pages, QR codes, or any generic "connect your accounts" entry point. |

Both can be used side by side: the retailer-selection URL is just another way into the same Link flow, and existing per-retailer Link URLs keep working unchanged.