diff --git a/CHANGELOG.md b/CHANGELOG.md
index cc6bc464f..c0a6ca856 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## Next Release
+
+- Sends card details in the request body instead of the URL query string when `referralCustomer.addCreditCardToUser` creates a Stripe token
+
 ## v8.8.0 (2026-06-25)
 
 - Adds `params` to `requestPin` ensuring users can pass `easypost_details` to the call
diff --git a/src/main/java/com/easypost/service/ReferralCustomerService.java b/src/main/java/com/easypost/service/ReferralCustomerService.java
index e21f2320f..721284cac 100644
--- a/src/main/java/com/easypost/service/ReferralCustomerService.java
+++ b/src/main/java/com/easypost/service/ReferralCustomerService.java
@@ -18,6 +18,7 @@
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
@@ -257,8 +258,10 @@ private static String createStripeToken(final String number, final int expiratio
         params.put("exp_year", String.valueOf(expirationYear));
         params.put("cvc", cvc);
 
-        String encodedURL = InternalUtilities.getEncodedURL(params, "card");
-        URL stripeUrl = new URL("https://api.stripe.com/v1/tokens?" + encodedURL);
+        // Card details must travel in the form-encoded request body, never in the URL,
+        // so they cannot end up in access logs, proxy logs, or Referer headers.
+        String encodedBody = InternalUtilities.getEncodedURL(params, "card");
+        URL stripeUrl = new URL("https://api.stripe.com/v1/tokens");
 
         HttpURLConnection conn;
         if (EasyPost._vcrUrlFunction != null) {
@@ -272,6 +275,10 @@ private static String createStripeToken(final String number, final int expiratio
         conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
         conn.setDoOutput(true);
 
+        try (OutputStream outputStream = conn.getOutputStream()) {
+            outputStream.write(encodedBody.getBytes(StandardCharsets.UTF_8));
+        }
+
         StringBuilder response;
 
         try (BufferedReader br = new BufferedReader(