# Track a payment link

Use URL parameters and UTM codes to track a payment link.

Modify your payment link with URL parameters and [Urchin Tracking Module (UTM)](https://en.wikipedia.org/wiki/UTM_parameters) codes to get insight into customer behaviors and your marketing strategy’s effectiveness. These tools help identify the source of your traffic and the marketing campaigns leading to the most conversions.

## Track campaigns with UTM codes 

Use UTM codes to track how customers find your site when they pay using your payment link. You can add the following UTM codes as parameters in the query string of your URL: `utm_source`, `utm_content`, `utm_medium`, `utm_term`, and `utm_campaign`.

| Parameter      | Description                                                                                                                         |
| -------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| `utm_source`   | Identifies where the traffic originated (for example, a website name, social media, or a search engine).                            |
| `utm_content`  | Identifies what content your customer chooses. Use this parameter to distinguish between links that point to the same payment page. |
| `utm_medium`   | Identifies the marketing medium that accesses your payment link (for example, email, cost per click (cpc), or other methods).       |
| `utm_term`     | Identifies specific search terms and keywords in your paid search ads.                                                              |
| `utm_campaign` | Identifies your marketing campaigns using the payment link URL.                                                                     |

To add UTM codes, specify `redirect` as your [confirmation behavior](https://docs.stripe.com/payment-links/post-payment.md#change-confirmation-behavior). When customers complete a payment, your redirect URL contains the UTM code parameters specified in your payment link URL. Here’s what a payment link looks like with an appended UTM codes: `https://buy.stripe.com/test_eVa5nPg1j1wmfXq5kr?utm_medium=earned_email&utm_source=marketo&utm_campaign=campaign_a`

> Construct UTM codes using alphanumeric characters, dashes, or underscores, ensuring they don’t exceed a 150-character limit. Invalid values are discreetly discarded, guaranteeing your payment links performance remains unaffected.

## Simplify reconciliation with a URL parameter 

You can simplify reconciliation with the `client_reference_id` URL parameter. Use URL parameters in the query string of your payment link URL. To configure URL parameters directly in the Dashboard [Payment Links](https://dashboard.stripe.com/payment-links) page:

1. Click the payment link you want to modify.
1. Click the down arrow of the **Copy** button and select **URL parameters**.
1. In the dialog, use the drop-down menu to select **Client reference ID**.
1. Enter a value that meets the requirements described in the following table to append the reference to your URL.
1. Copy the amended URL for use in your integration.

| Parameter             | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | Syntax                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| --------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `client_reference_id` | Use `client_reference_id` to attach a unique string of your choice to the Checkout Session. This can be a customer ID or a cart ID (or similar), and you can use it to reconcile the Session with your internal systems. If you add this parameter to your payment link, it’s sent in the [checkout.session.completed](https://docs.stripe.com/api/events/types.md#event_types-checkout.session.completed) *webhook* (A webhook is a real-time push notification sent to your application as a JSON payload through HTTPS requests) after payment completion. | `client_reference_id` can be composed of alphanumeric characters, dashes, or underscores, and be any value up to 200 characters. Invalid values are silently dropped, but your payment page continues to work as expected.

  Depending on how you share your Payment Links, they might show up in unexpected places. If you add a client reference ID to a payment link, make sure that it doesn’t include sensitive information or secrets such as passwords or API keys. Only share Payment Links that have URL parameters with intended recipients. |

## Track payments with the API

When customers use a payment link to complete a payment, Stripe sends a [checkout.session.completed](https://docs.stripe.com/api/events/types.md#event_types-checkout.session.completed) webhook that you can use for fulfillment and reconciliation. Learn more about [receiving Stripe events in your integration](https://docs.stripe.com/webhooks.md).

Make sure to listen to additional webhooks in case you’ve enabled payment methods like bank debits or vouchers, which can take 2-14 days to confirm the payment. For more information, see our guide on [fulfilling orders after a customer pays](https://docs.stripe.com/checkout/fulfillment.md).

After a customer completes a purchase, you can redirect them to a URL or display a custom message by setting [after_completion](https://docs.stripe.com/api/payment-link/create.md#create_payment_link-after_completion) on the payment link.

```curl
curl https://api.stripe.com/v1/payment_links \
  -u "<<YOUR_SECRET_KEY>>:" \
  -d "line_items[0][price]={{PRICE_ID}}" \
  -d "line_items[0][quantity]=1" \
  -d "after_completion[type]=redirect" \
  --data-urlencode "after_completion[redirect][url]=https://example.com"
```