diff --git a/test/api/v3/integration/groups/POST-groups_groupId_join.js b/test/api/v3/integration/groups/POST-groups_groupId_join.js
index aa26c10289..2c36d12f19 100644
--- a/test/api/v3/integration/groups/POST-groups_groupId_join.js
+++ b/test/api/v3/integration/groups/POST-groups_groupId_join.js
@@ -1,8 +1,20 @@
 import {
   generateUser,
+  translate as t,
 } from '../../../../helpers/api-integration.helper';
+import { v4 as generateUUID } from 'uuid';
 
 describe('POST /group/:groupId/join', () => {
+  it('returns error when groupId is not for a valid group', async () => {
+    let joiningUser = await generateUser();
+
+    await expect(joiningUser.post(`/groups/${generateUUID()}/join`)).to.eventually.be.rejected.and.eql({
+      code: 404,
+      error: 'NotFound',
+      message: t('groupNotFound'),
+    });
+  });
+
   context('Accepting invitation to a guild', () => {
     let user, invitedUser, guild;
 
@@ -11,24 +23,68 @@ describe('POST /group/:groupId/join', () => {
       guild = await user.post('/groups', {
         name: 'Test Guild',
         type: 'guild',
-      });
-      invitedUser = await generateUser({
-        'invitations.guilds': [{ id: guild._id}],
+        privacy: 'private',
       });
     });
 
-    it('does not give basilist quest to inviter when joining a guild', async () => {
-      await invitedUser.post(`/groups/${guild._id}/join`);
+    it('returns error when user is not invited to private guild', async () => {
+      let joiningUser = await generateUser();
 
-      await expect(user.get('/user')).to.eventually.not.have.deep.property('items.quests.basilist');
+      await expect(joiningUser.post(`/groups/${guild._id}/join`)).to.eventually.be.rejected.and.eql({
+        code: 401,
+        error: 'NotAuthorized',
+        message: t('messageGroupRequiresInvite'),
+      });
     });
 
-    it('does not increment basilist quest count to inviter with basilist when joining a guild', async () => {
-      user.update({ 'items.quests.basilist': 1 });
+    it('allows non-invited users to join public guilds', async () => {
+      await user.update({balance: 1});
+      guild = await user.post('/groups', {
+        name: 'Test Guild',
+        type: 'guild',
+        privacy: 'public',
+      });
 
-      await invitedUser.post(`/groups/${guild._id}/join`);
+      let joiningUser = await generateUser();
+      await joiningUser.post(`/groups/${guild._id}/join`);
 
-      await expect(user.get('/user')).to.eventually.have.deep.property('items.quests.basilist', 1);
+      await expect(joiningUser.get('/user')).to.eventually.have.property('guilds').to.include(guild._id);
+    });
+
+    context('User is invited', () => {
+      beforeEach(async () => {
+        invitedUser = await generateUser({
+          'invitations.guilds': [{ id: guild._id}],
+        });
+      });
+
+      it('allows invited user to join private guilds', async () => {
+        await invitedUser.post(`/groups/${guild._id}/join`);
+
+        await expect(invitedUser.get('/user')).to.eventually.have.property('guilds').to.include(guild._id);
+      });
+
+      it('clears invitation from user when joining guilds', async () => {
+        await invitedUser.post(`/groups/${guild._id}/join`);
+
+        await expect(invitedUser.get('/user'))
+          .to.eventually.have.deep.property('invitations.guilds')
+          .to.not.include({id: guild._id});
+      });
+
+      it('does not give basilist quest to inviter when joining a guild', async () => {
+        await invitedUser.post(`/groups/${guild._id}/join`);
+
+        await expect(user.get('/user')).to.eventually.not.have.deep.property('items.quests.basilist');
+      });
+
+      it('does not increment basilist quest count to inviter with basilist when joining a guild', async () => {
+        await user.update({ 'items.quests.basilist': 1 });
+
+        await invitedUser.post(`/groups/${guild._id}/join`);
+
+        await expect(user.get('/user')).to.eventually.have.deep.property('items.quests.basilist', 1);
+      });
     });
   });
 
@@ -41,23 +97,50 @@ describe('POST /group/:groupId/join', () => {
         name: 'Test Party',
         type: 'party',
       });
-      invitedUser = await generateUser({
-        'invitations.party': { id: party._id, inviter: user._id },
+    });
+
+    it('returns error when user is not invited to party', async () => {
+      let joiningUser = await generateUser();
+
+      await expect(joiningUser.post(`/groups/${party._id}/join`)).to.eventually.be.rejected.and.eql({
+        code: 401,
+        error: 'NotAuthorized',
+        message: t('messageGroupRequiresInvite'),
       });
     });
 
-    it('gives basilist quest item to the inviter when joining a party', async () => {
-      await invitedUser.post(`/groups/${party._id}/join`);
+    context('User is invited', () => {
+      beforeEach(async () => {
+        invitedUser = await generateUser({
+          'invitations.party': { id: party._id, inviter: user._id },
+        });
+      });
 
-      await expect(user.get('/user')).to.eventually.have.deep.property('items.quests.basilist', 1);
-    });
+      it('allows invited user to join party', async () => {
+        await invitedUser.post(`/groups/${party._id}/join`);
 
-    it('increments basilist quest item count to inviter when joining a party', async () => {
-      user.update({'items.quests.basilist': 1 });
+        await expect(invitedUser.get('/user')).to.eventually.have.deep.property('party._id', party._id);
+      });
 
-      await invitedUser.post(`/groups/${party._id}/join`);
+      it('clears invitation from user when joining party', async () => {
+        await invitedUser.post(`/groups/${party._id}/join`);
 
-      await expect(user.get('/user')).to.eventually.have.deep.property('items.quests.basilist', 2);
+        await expect(invitedUser.get('/user')).to.eventually.not.have.deep.property('invitations.party.id');
+      });
+
+      it('gives basilist quest item to the inviter when joining a party', async () => {
+        await invitedUser.post(`/groups/${party._id}/join`);
+
+        await expect(user.get('/user')).to.eventually.have.deep.property('items.quests.basilist', 1);
+      });
+
+      it('increments basilist quest item count to inviter when joining a party', async () => {
+        await user.update({'items.quests.basilist': 1 });
+
+        await invitedUser.post(`/groups/${party._id}/join`);
+
+        await expect(user.get('/user')).to.eventually.have.deep.property('items.quests.basilist', 2);
+      });
     });
   });
 });
diff --git a/website/src/controllers/api-v3/groups.js b/website/src/controllers/api-v3/groups.js
index a61c56e26c..80b2972217 100644
--- a/website/src/controllers/api-v3/groups.js
+++ b/website/src/controllers/api-v3/groups.js
@@ -228,7 +228,7 @@ api.joinGroup = {
       user.party._id = group._id; // Set group as user's party
 
       isUserInvited = true;
-    } else if (group.type === 'guild' && user.invitations.guilds) {
+    } else if (group.type === 'guild') {
       let i = _.findIndex(user.invitations.guilds, {id: group._id});
 
       if (i !== -1) {