diff --git a/test/api/v3/unit/libs/payments/amazon/subscribe.test.js b/test/api/v3/unit/libs/payments/amazon/subscribe.test.js
index 930c64d06a..b0ae072880 100644
--- a/test/api/v3/unit/libs/payments/amazon/subscribe.test.js
+++ b/test/api/v3/unit/libs/payments/amazon/subscribe.test.js
@@ -216,6 +216,9 @@ describe('Amazon Payments - Subscribe', () => {
   });
 
   it('subscribes with amazon', async () => {
+    user.guilds.push(groupId);
+    await user.save();
+
     await amzLib.subscribe({
       billingAgreementId,
       sub,
@@ -241,8 +244,13 @@ describe('Amazon Payments - Subscribe', () => {
     user = new User();
     user.guilds.push(groupId);
     await user.save();
-    group.memberCount = 2;
-    await group.save();
+
+    // Add existing users
+    user = new User();
+    user.guilds.push(groupId);
+    await user.save();
+
+    // Set expected amount
     sub.key = 'group_monthly';
     sub.price = 9;
     amount = 12;
diff --git a/test/api/v3/unit/libs/payments/stripe/checkout-subscription.test.js b/test/api/v3/unit/libs/payments/stripe/checkout-subscription.test.js
index 7271b1dbd3..411acbedaf 100644
--- a/test/api/v3/unit/libs/payments/stripe/checkout-subscription.test.js
+++ b/test/api/v3/unit/libs/payments/stripe/checkout-subscription.test.js
@@ -227,6 +227,11 @@ describe('checkout with subscription', () => {
     sub = data.sub;
     groupId = group._id;
     email = 'test@test.com';
+
+    // Add user to group
+    user.guilds.push(groupId);
+    await user.save();
+
     headers = {};
 
     await stripePayments.checkout({
@@ -267,9 +272,15 @@ describe('checkout with subscription', () => {
     groupId = group._id;
     email = 'test@test.com';
     headers = {};
+
+    // Add user to group
+    user.guilds.push(groupId);
+    await user.save();
+
     user = new User();
     user.guilds.push(groupId);
     await user.save();
+
     group.memberCount = 2;
     await group.save();
 
diff --git a/website/server/libs/amazonPayments.js b/website/server/libs/amazonPayments.js
index f71185526f..75ccddcecc 100644
--- a/website/server/libs/amazonPayments.js
+++ b/website/server/libs/amazonPayments.js
@@ -270,10 +270,10 @@ api.subscribe = async function subscribe (options) {
   let priceOfSingleMember = 3;
 
   if (groupId) {
-    let groupFields = basicGroupFields.concat(' purchased');
-    let group = await Group.getGroup({user, groupId, populateLeader: false, groupFields});
-
-    amount = sub.price + (group.memberCount - leaderCount) * priceOfSingleMember;
+    const groupFields = basicGroupFields.concat(' purchased');
+    const group = await Group.getGroup({user, groupId, populateLeader: false, groupFields});
+    const membersCount = await group.getMemberCount();
+    amount = sub.price + (membersCount - leaderCount) * priceOfSingleMember;
   }
 
   await this.setBillingAgreementDetails({
diff --git a/website/server/libs/stripePayments.js b/website/server/libs/stripePayments.js
index 63b2041ca3..7cf6c0b75e 100644
--- a/website/server/libs/stripePayments.js
+++ b/website/server/libs/stripePayments.js
@@ -97,9 +97,10 @@ api.checkout = async function checkout (options, stripeInc) {
 
     if (groupId) {
       customerObject.quantity = sub.quantity;
-      let groupFields = basicGroupFields.concat(' purchased');
-      let group = await Group.getGroup({user, groupId, populateLeader: false, groupFields});
-      customerObject.quantity = group.memberCount + sub.quantity - 1;
+      const groupFields = basicGroupFields.concat(' purchased');
+      const group = await Group.getGroup({user, groupId, populateLeader: false, groupFields});
+      const membersCount = await group.getMemberCount();
+      customerObject.quantity = membersCount + sub.quantity - 1;
     }
 
     response = await stripeApi.customers.create(customerObject);
diff --git a/website/server/models/group.js b/website/server/models/group.js
index 45c7c99235..3a0e8df2c5 100644
--- a/website/server/models/group.js
+++ b/website/server/models/group.js
@@ -442,6 +442,16 @@ schema.methods.isMember = function isGroupMember (user) {
   }
 };
 
+schema.methods.getMemberCount = async function getMemberCount () {
+  let query = { guilds: this._id };
+
+  if (this.type === 'party') {
+    query = { 'party._id': this._id };
+  }
+
+  return await User.count(query).exec();
+};
+
 export function chatDefaults (msg, user) {
   let message = {
     id: shared.uuid(),