diff --git a/lib/providers/stripe.ts b/lib/providers/stripe.ts
index 15abf96..5a91b70 100644
--- a/lib/providers/stripe.ts
+++ b/lib/providers/stripe.ts
@@ -1,5 +1,7 @@
 import 'std/dotenv/load.ts';
 
+import { baseUrl, jsonToFormUrlEncoded } from '/lib/utils.ts';
+
 const STRIPE_API_KEY = Deno.env.get('STRIPE_API_KEY') || '';
 
 interface StripeCustomer {
@@ -60,11 +62,23 @@ interface StripeResponse {
   data: any[];
 }
 
-function getApiRequestHeaders() {
+interface StripeCustomerPortalSession {
+  id: string;
+  object: 'billing_portal.session';
+  configuration: string;
+  created: number;
+  customer: string;
+  return_url: string;
+  url: string;
+}
+
+function getApiRequestHeaders(method: 'GET' | 'POST') {
   return {
     'Authorization': `Bearer ${STRIPE_API_KEY}`,
     'Accept': 'application/json; charset=utf-8',
-    'Content-Type': 'application/json; charset=utf-8',
+    'Content-Type': method === 'GET'
+      ? 'application/json; charset=utf-8'
+      : 'application/x-www-form-urlencoded; charset=utf-8',
   };
 }
 
@@ -76,7 +90,7 @@ export async function getSubscriptions() {
 
   const response = await fetch(`https://api.stripe.com/v1/subscriptions?${searchParams.toString()}`, {
     method: 'GET',
-    headers: getApiRequestHeaders(),
+    headers: getApiRequestHeaders('GET'),
   });
 
   const result = (await response.json()) as StripeResponse;
@@ -90,3 +104,25 @@ export async function getSubscriptions() {
 
   return subscriptions;
 }
+
+export async function createCustomerPortalSession(stripeCustomerId: string) {
+  const customerPortalSession = {
+    customer: stripeCustomerId,
+    return_url: baseUrl,
+  };
+
+  const response = await fetch(`https://api.stripe.com/v1/billing_portal/sessions`, {
+    method: 'POST',
+    headers: getApiRequestHeaders('POST'),
+    body: jsonToFormUrlEncoded(customerPortalSession),
+  });
+
+  const result = (await response.json()) as StripeCustomerPortalSession;
+
+  if (!result?.url) {
+    console.log(JSON.stringify({ result }, null, 2));
+    throw new Error(`Failed to make API request: "${result}"`);
+  }
+
+  return result.url;
+}
diff --git a/lib/utils.ts b/lib/utils.ts
index 2c9b625..57f5135 100644
--- a/lib/utils.ts
+++ b/lib/utils.ts
@@ -72,8 +72,6 @@ function basicLayout(htmlContent: string, { currentPath, titlePrefix, descriptio
         window.app = {
           STRIPE_MONTHLY_URL: '${STRIPE_MONTHLY_URL}',
           STRIPE_YEARLY_URL: '${STRIPE_YEARLY_URL}',
-          STRIPE_CUSTOMER_URL: '${STRIPE_CUSTOMER_URL}',
-          PAYPAL_CUSTOMER_URL: '${PAYPAL_CUSTOMER_URL}',
         };
       </script>
       <script src="/public/js/script.js"></script>
@@ -185,3 +183,15 @@ export function splitArrayInChunks<T = any>(array: T[], chunkLength: number) {
 
   return chunks;
 }
+
+// Because new URLSearchParams(Object.entries(object)).toString() doesn't work recursively
+export function jsonToFormUrlEncoded(object: any, key = '', list: string[] = []) {
+  if (typeof (object) === 'object') {
+    for (const subKey in object) {
+      jsonToFormUrlEncoded(object[subKey], key ? `${key}[${subKey}]` : subKey, list);
+    }
+  } else {
+    list.push(`${key}=${encodeURIComponent(object)}`);
+  }
+  return list.join('&');
+}
diff --git a/lib/utils_test.ts b/lib/utils_test.ts
index fbac83c..af1029a 100644
--- a/lib/utils_test.ts
+++ b/lib/utils_test.ts
@@ -1,5 +1,5 @@
-import { assertEquals } from 'std/testing/asserts.ts';
-import { escapeHtml, generateRandomCode, splitArrayInChunks } from './utils.ts';
+import { assertEquals } from 'std/assert/assert_equals.ts';
+import { escapeHtml, generateRandomCode, jsonToFormUrlEncoded, splitArrayInChunks } from './utils.ts';
 
 Deno.test('that escapeHtml works', () => {
   const tests = [
@@ -102,3 +102,69 @@ Deno.test('that splitArrayInChunks works', () => {
     assertEquals(output, test.expected);
   }
 });
+
+Deno.test('that jsonToFormUrlEncoded works', () => {
+  const tests = [
+    {
+      input: {
+        user: {
+          id: 'uuid-1',
+          role: 'user',
+          groups: [
+            {
+              id: 'uuid-1',
+              permissions: ['view_banking', 'edit_banking'],
+            },
+            {
+              id: 'uuid-2',
+              permissions: ['view_employees'],
+            },
+          ],
+        },
+        permissions: ['view_banking'],
+      },
+      expected:
+        'user[id]=uuid-1&user[role]=user&user[groups][0][id]=uuid-1&user[groups][0][permissions][0]=view_banking&user[groups][0][permissions][1]=edit_banking&user[groups][1][id]=uuid-2&user[groups][1][permissions][0]=view_employees&permissions[0]=view_banking',
+    },
+    {
+      input: {
+        user: {
+          id: 'uuid-1',
+          role: 'user',
+          groups: ['all', 'there'],
+        },
+        permissions: ['view_employees'],
+      },
+      expected:
+        'user[id]=uuid-1&user[role]=user&user[groups][0]=all&user[groups][1]=there&permissions[0]=view_employees',
+    },
+    {
+      input: {
+        user: {
+          id: 'uuid-1',
+          role: 'admin',
+          groups: [],
+        },
+        permissions: ['edit_banking'],
+      },
+      expected: 'user[id]=uuid-1&user[role]=admin&permissions[0]=edit_banking',
+    },
+    {
+      input: [{ something: 1 }],
+      expected: '0[something]=1',
+    },
+    {
+      input: { something: 1 },
+      expected: 'something=1',
+    },
+    {
+      input: { something: [1, 2] },
+      expected: 'something[0]=1&something[1]=2',
+    },
+  ];
+
+  for (const test of tests) {
+    const output = jsonToFormUrlEncoded(test.input);
+    assertEquals(output, test.expected);
+  }
+});
diff --git a/pages/api/user.ts b/pages/api/user.ts
index 0a5abef..077b76a 100644
--- a/pages/api/user.ts
+++ b/pages/api/user.ts
@@ -11,7 +11,7 @@ import {
   validateUserAndSession,
   validateVerificationCode,
 } from '/lib/data-utils.ts';
-import { EncryptedData } from '/lib/types.ts';
+import { EncryptedData, User } from '/lib/types.ts';
 import {
   sendUpdateEmailInProviderEmail,
   sendVerifyDeleteAccountEmail,
@@ -19,6 +19,8 @@ import {
   sendVerifyUpdatePasswordEmail,
 } from '/lib/providers/postmark.ts';
 import { SupportedCurrencySymbol, validateEmail } from '/public/ts/utils.ts';
+import { PAYPAL_CUSTOMER_URL, STRIPE_CUSTOMER_URL } from '/lib/utils.ts';
+import { createCustomerPortalSession } from '/lib/providers/stripe.ts';
 
 async function createUserAction(request: Request) {
   const { email, encrypted_key_pair }: { email: string; encrypted_key_pair: EncryptedData } = await request.json();
@@ -190,5 +192,24 @@ export async function pageContent(request: Request) {
 
   await updateSession(session);
 
-  return new Response(JSON.stringify(user), { headers: { 'Content-Type': 'application/json; charset=utf-8' } });
+  let customerPortalUrl = '';
+
+  if (user.subscription.external.paypal) {
+    customerPortalUrl = PAYPAL_CUSTOMER_URL;
+  } else if (user.subscription.external.stripe) {
+    customerPortalUrl = STRIPE_CUSTOMER_URL;
+
+    if (user.subscription.external.stripe.user_id) {
+      try {
+        customerPortalUrl = await createCustomerPortalSession(user.subscription.external.stripe.user_id);
+      } catch (error) {
+        console.error(`Failed to create custom Stripe customer portal URL: ${error}`);
+        console.log(error);
+      }
+    }
+  }
+
+  const finalResult: User & { customerPortalUrl: string } = { ...user, customerPortalUrl };
+
+  return new Response(JSON.stringify(finalResult), { headers: { 'Content-Type': 'application/json; charset=utf-8' } });
 }
diff --git a/public/ts/billing.ts b/public/ts/billing.ts
index f542dac..4feb389 100644
--- a/public/ts/billing.ts
+++ b/public/ts/billing.ts
@@ -11,14 +11,7 @@ document.addEventListener('app-loaded', async () => {
     event.preventDefault();
     event.stopPropagation();
 
-    let updateUrl = '';
-
-    if (user?.subscription.external.stripe) {
-      updateUrl = window.app.STRIPE_CUSTOMER_URL;
-    }
-    if (user?.subscription.external.paypal) {
-      updateUrl = window.app.PAYPAL_CUSTOMER_URL;
-    }
+    const updateUrl = user?.customerPortalUrl;
 
     if (!updateUrl) {
       showNotification('You need to reach out in order to update your subscription, sorry!', 'error');
@@ -32,14 +25,7 @@ document.addEventListener('app-loaded', async () => {
     event.preventDefault();
     event.stopPropagation();
 
-    let cancelUrl = '';
-
-    if (user?.subscription.external.stripe) {
-      cancelUrl = window.app.STRIPE_CUSTOMER_URL;
-    }
-    if (user?.subscription.external.paypal) {
-      cancelUrl = window.app.PAYPAL_CUSTOMER_URL;
-    }
+    const cancelUrl = user?.customerPortalUrl;
 
     if (!cancelUrl) {
       showNotification('You need to reach out in order to cancel your subscription, sorry!', 'error');
@@ -53,14 +39,7 @@ document.addEventListener('app-loaded', async () => {
     event.preventDefault();
     event.stopPropagation();
 
-    let updateUrl = '';
-
-    if (user?.subscription.external.stripe) {
-      updateUrl = window.app.STRIPE_CUSTOMER_URL;
-    }
-    if (user?.subscription.external.paypal) {
-      updateUrl = window.app.PAYPAL_CUSTOMER_URL;
-    }
+    const updateUrl = user?.customerPortalUrl;
 
     if (!updateUrl) {
       showNotification('You need to reach out in order to resume your subscription, sorry!', 'error');
diff --git a/public/ts/pricing.ts b/public/ts/pricing.ts
index dca40ea..8dfd6e1 100644
--- a/public/ts/pricing.ts
+++ b/public/ts/pricing.ts
@@ -45,7 +45,9 @@ document.addEventListener('app-loaded', async () => {
       return;
     }
 
-    window.location.href = window.app.STRIPE_MONTHLY_URL;
+    window.location.href = `${window.app.STRIPE_MONTHLY_URL}?client_reference_id=${user.id}&customer_email=${
+      encodeURIComponent(user.email)
+    }`;
   }
 
   async function subscribeYearly(event: Event) {
@@ -59,7 +61,9 @@ document.addEventListener('app-loaded', async () => {
       return;
     }
 
-    window.location.href = window.app.STRIPE_YEARLY_URL;
+    window.location.href = `${window.app.STRIPE_YEARLY_URL}?client_reference_id=${user.id}&customer_email=${
+      encodeURIComponent(user.email)
+    }`;
   }
 
   function getValidSubscriptionHtmlElement() {
diff --git a/public/ts/utils.ts b/public/ts/utils.ts
index 215ef11..43336a2 100644
--- a/public/ts/utils.ts
+++ b/public/ts/utils.ts
@@ -12,8 +12,6 @@ declare global {
 export interface App {
   STRIPE_MONTHLY_URL: string;
   STRIPE_YEARLY_URL: string;
-  STRIPE_CUSTOMER_URL: string;
-  PAYPAL_CUSTOMER_URL: string;
   isLoggedIn: boolean;
   showLoading: () => void;
   hideLoading: () => void;
@@ -154,7 +152,7 @@ async function getUser() {
     searchParams.set('email', session.email);
 
     const response = await fetch(`/api/user?${searchParams.toString()}`, { method: 'GET', headers });
-    const user = (await response.json()) as User;
+    const user = (await response.json()) as User & { customerPortalUrl: string };
 
     return user;
   } catch (_error) {