diff --git a/src/functions/attend-event/handler.ts b/src/functions/attend-event/handler.ts
index bd3bca6..cd33631 100644
--- a/src/functions/attend-event/handler.ts
+++ b/src/functions/attend-event/handler.ts
@@ -5,7 +5,8 @@ import { middyfy } from '@libs/lambda';
 import schema from './schema';
 
 import { MongoDB, validateToken, ensureRoles } from '../../util';
-import type { UserDocument } from 'src/types';
+import type { UserDocument } from '../../types';
+import { RegistrationStatus } from '../../types';
 import * as path from 'path';
 import * as dotenv from 'dotenv';
 dotenv.config({ path: path.resolve(process.cwd(), '.env') });
@@ -63,7 +64,7 @@ const attendEvent: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (ev
       };
     }
 
-    if (attendEvent.registration_status != 'checked_in') {
+    if (attendEvent.registration_status != RegistrationStatus.CHECKED_IN) {
       return {
         statusCode: 409,
         body: JSON.stringify({
diff --git a/src/functions/discord/handler.ts b/src/functions/discord/handler.ts
index bd75306..3b07833 100644
--- a/src/functions/discord/handler.ts
+++ b/src/functions/discord/handler.ts
@@ -4,6 +4,7 @@ import { middyfy } from '@libs/lambda';
 import schema from './schema';
 
 import { MongoDB, validateToken } from '../../util';
+import { RegistrationStatus } from '../../types';
 import * as discordAPI from '@libs/discord';
 
 import * as path from 'path';
@@ -41,7 +42,7 @@ const discord: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (event)
     const discordUser = await discordAPI.getDiscordUser(tokens.accessToken);
     await discordAPI.updateDiscordMetadata(tokens.accessToken, user.first_name + ' ' + user.last_name, {
       verified: new Date().toISOString(),
-      checked_in: user.registration_status == 'checked_in' ? 1 : 0,
+      checked_in: user.registration_status == RegistrationStatus.CHECKED_IN ? 1 : 0,
     });
 
     await users.updateOne(
diff --git a/src/functions/teams/create/handler.ts b/src/functions/teams/create/handler.ts
index 974e972..c29227c 100644
--- a/src/functions/teams/create/handler.ts
+++ b/src/functions/teams/create/handler.ts
@@ -2,7 +2,7 @@ import type { ValidatedEventAPIGatewayProxyEvent } from '@libs/api-gateway';
 import { middyfy } from '@libs/lambda';
 import schema from './schema';
 import { MongoDB, validateToken, teamInviteLogic } from '../../../util';
-import { UserDocument, TeamDocument } from 'src/types';
+import { UserDocument, TeamDocument, RegistrationStatus, TeamStatus, TeamRole } from '../../../types';
 import { v4 as uuidv4 } from 'uuid';
 import * as path from 'path';
 import * as dotenv from 'dotenv';
@@ -75,7 +75,11 @@ const teamsCreate: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (ev
     }
 
     // Check if auth user has valid registration status for team creation
-    const validStatesForTeamCreation = ['registered', 'confirmation', 'coming'];
+    const validStatesForTeamCreation = [
+      RegistrationStatus.REGISTERED,
+      RegistrationStatus.CONFIRMATION,
+      RegistrationStatus.COMING,
+    ];
     if (!validStatesForTeamCreation.includes(authUser.registration_status)) {
       return {
         statusCode: 400,
@@ -87,7 +91,7 @@ const teamsCreate: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (ev
     }
 
     // Check if user already leads a team
-    if (authUser.team_info?.role === 'leader') {
+    if (authUser.team_info?.role === TeamRole.LEADER) {
       return {
         statusCode: 400,
         body: JSON.stringify({
@@ -188,7 +192,7 @@ const teamsCreate: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (ev
       team_id: teamId,
       leader_email: event.body.auth_email.toLowerCase(),
       members: [],
-      status: 'Active' as const,
+      status: TeamStatus.ACTIVE,
       team_name: teamName,
       created: new Date(),
       updated: new Date(),
@@ -210,7 +214,7 @@ const teamsCreate: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (ev
               confirmed_team: true,
               team_info: {
                 team_id: teamId,
-                role: 'leader' as const,
+                role: TeamRole.LEADER,
                 pending_invites: [],
               },
             },
diff --git a/src/functions/teams/join/handler.ts b/src/functions/teams/join/handler.ts
index 40dd377..2f6b6c4 100644
--- a/src/functions/teams/join/handler.ts
+++ b/src/functions/teams/join/handler.ts
@@ -2,7 +2,7 @@ import type { ValidatedEventAPIGatewayProxyEvent } from '@libs/api-gateway';
 import { middyfy } from '@libs/lambda';
 import schema from './schema';
 import { MongoDB, validateToken } from '../../../util';
-import { UserDocument, TeamDocument } from '../../../types';
+import { UserDocument, TeamDocument, TeamStatus, TeamRole } from '../../../types';
 import * as path from 'path';
 import * as dotenv from 'dotenv';
 dotenv.config({ path: path.resolve(process.cwd(), '.env') });
@@ -76,7 +76,7 @@ const teamsJoin: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (even
       };
     }
 
-    if (team.status !== 'Active') {
+    if (team.status !== TeamStatus.ACTIVE) {
       return {
         statusCode: 400,
         body: JSON.stringify({
@@ -117,7 +117,7 @@ const teamsJoin: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (even
           confirmed_team: true,
           team_info: {
             team_id: event.body.team_id,
-            role: 'member',
+            role: TeamRole.MEMBER,
             pending_invites: remainingInvites,
           },
         },
diff --git a/src/functions/teams/member-removal/handler.ts b/src/functions/teams/member-removal/handler.ts
index 683154c..647cfa4 100644
--- a/src/functions/teams/member-removal/handler.ts
+++ b/src/functions/teams/member-removal/handler.ts
@@ -4,7 +4,7 @@ import schema from './schema';
 import { MongoDB, validateToken } from '../../../util';
 import * as path from 'path';
 import * as dotenv from 'dotenv';
-import { UserDocument, TeamDocument } from '../../../types';
+import { UserDocument, TeamDocument, TeamStatus } from '../../../types';
 dotenv.config({ path: path.resolve(process.cwd(), '.env') });
 
 const teamsMemberRemoval: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (event) => {
@@ -52,7 +52,7 @@ const teamsMemberRemoval: ValidatedEventAPIGatewayProxyEvent<typeof schema> = as
     }
 
     // Check if team is active
-    if (team.status !== 'Active') {
+    if (team.status !== TeamStatus.ACTIVE) {
       return {
         statusCode: 400,
         body: JSON.stringify({
diff --git a/src/functions/teams/read/handler.ts b/src/functions/teams/read/handler.ts
index a29c59b..bbe4593 100644
--- a/src/functions/teams/read/handler.ts
+++ b/src/functions/teams/read/handler.ts
@@ -5,6 +5,7 @@ import schema from './schema';
 
 import { ensureRoles, MongoDB, validateToken } from '../../../util';
 import type { UserDocument, TeamDocument } from '../../../types';
+import { TeamStatus } from '../../../types';
 
 import * as path from 'path';
 import * as dotenv from 'dotenv';
@@ -98,7 +99,7 @@ const teamsRead: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (even
       };
     }
 
-    if (team.status !== 'Active') {
+    if (team.status !== TeamStatus.ACTIVE) {
       return {
         statusCode: 400,
         body: JSON.stringify({
diff --git a/src/functions/update/handler.ts b/src/functions/update/handler.ts
index c5e1c00..9759ad2 100644
--- a/src/functions/update/handler.ts
+++ b/src/functions/update/handler.ts
@@ -7,6 +7,7 @@ import schema from './schema';
 import { validateEmail } from '../../helper';
 
 import { MongoDB, validateToken, ensureRoles } from '../../util';
+import { RegistrationStatus } from '../../types';
 import * as path from 'path';
 import * as dotenv from 'dotenv';
 import { Document, WithId } from 'mongodb';
@@ -94,7 +95,7 @@ const update: ValidatedEventAPIGatewayProxyEvent<typeof schema> = async (event)
     }
 
     // add registered_at time if status is updated
-    if (event.body.updates?.$set?.registration_status == 'registered')
+    if (event.body.updates?.$set?.registration_status == RegistrationStatus.REGISTERED)
       event.body.updates.$set['registered_at'] = new Date().toISOString();
 
     // call updates
@@ -150,49 +151,68 @@ interface Updates {
 // 2. no alteration to fields such as: _id, password,
 
 const registrationStatusGraph = {
-  unregistered: ['registered'],
-  registered: ['rejected', 'confirmation', 'waitlist'],
-  confirmation: ['coming', 'not_coming'],
-  rejected: ['checked_in'],
-  coming: ['not_coming', 'confirmed'],
-  not_coming: ['coming', 'waitlist'],
-  confirmed: ['checked_in'],
-  waitlist: ['checked_in'],
-  checked_in: [],
+  [RegistrationStatus.UNREGISTERED]: [RegistrationStatus.REGISTERED],
+  [RegistrationStatus.REGISTERED]: [
+    RegistrationStatus.REJECTED,
+    RegistrationStatus.CONFIRMATION,
+    RegistrationStatus.WAITLIST,
+  ],
+  [RegistrationStatus.CONFIRMATION]: [RegistrationStatus.COMING, RegistrationStatus.NOT_COMING],
+  [RegistrationStatus.REJECTED]: [RegistrationStatus.CHECKED_IN],
+  [RegistrationStatus.COMING]: [RegistrationStatus.NOT_COMING, RegistrationStatus.CONFIRMED],
+  [RegistrationStatus.NOT_COMING]: [RegistrationStatus.COMING, RegistrationStatus.WAITLIST],
+  [RegistrationStatus.CONFIRMED]: [RegistrationStatus.CHECKED_IN],
+  [RegistrationStatus.WAITLIST]: [RegistrationStatus.CHECKED_IN],
+  [RegistrationStatus.CHECKED_IN]: [],
 };
 
-function isValidRegistrationStatusUpdate(current: string, goal: string): boolean {
+function isValidRegistrationStatusUpdate(current: RegistrationStatus, goal: RegistrationStatus): boolean {
   if (current in registrationStatusGraph) return registrationStatusGraph[current].includes(goal);
   return false;
 }
 
 // return true or false whether the proposed update is valid or not
 
-function validateUpdates(updates: Updates, registrationStatus?: string, user?: WithId<Document>): boolean | string {
+function validateUpdates(
+  updates: Updates,
+  registrationStatus?: RegistrationStatus,
+  user?: WithId<Document>
+): boolean | string {
   const setUpdates = updates.$set;
   if (setUpdates) {
     if ('registration_status' in setUpdates) {
       const currentDate = new Date();
       const goalStatus = setUpdates.registration_status as string;
 
-      if (goalStatus === 'checked_in') {
+      if (goalStatus === RegistrationStatus.CHECKED_IN) {
         if (currentDate > CHECK_IN_CUT_OFF)
           return `Registration is closed. The cutoff date was ${CHECK_IN_CUT_OFF.toLocaleString()}.`;
       }
 
-      const atleastRegistered = ['confirmed', 'waitlist', 'registered', 'coming'].includes(
-        registrationStatus || 'unregistered'
-      );
-      if (goalStatus === 'checked_in' && atleastRegistered) {
-        if (currentDate >= CHECK_IN_START_DATE || registrationStatus === 'confirmed') return true;
+      const atleastRegistered = [
+        RegistrationStatus.CONFIRMED,
+        RegistrationStatus.WAITLIST,
+        RegistrationStatus.REGISTERED,
+        RegistrationStatus.COMING,
+      ].includes(registrationStatus || RegistrationStatus.UNREGISTERED);
+      if (goalStatus === RegistrationStatus.CHECKED_IN && atleastRegistered) {
+        if (currentDate >= CHECK_IN_START_DATE || registrationStatus === RegistrationStatus.CONFIRMED) return true;
         else
           return `Current status of this user is ${registrationStatus}. Check-in will be available after ${CHECK_IN_START_DATE.toLocaleString()}.`;
       }
 
-      if (!isValidRegistrationStatusUpdate(registrationStatus || 'unregistered', goalStatus))
+      if (
+        !isValidRegistrationStatusUpdate(
+          registrationStatus || RegistrationStatus.UNREGISTERED,
+          goalStatus as RegistrationStatus
+        )
+      )
         return `Invalid registration status update from ${registrationStatus} to ${goalStatus}`;
 
-      if ((registrationStatus === undefined || registrationStatus == 'unregistered') && goalStatus === 'registered') {
+      if (
+        (registrationStatus === undefined || registrationStatus == RegistrationStatus.UNREGISTERED) &&
+        goalStatus === RegistrationStatus.REGISTERED
+      ) {
         if (
           [
             'email',
diff --git a/src/types.ts b/src/types.ts
index 920fb78..61ce0c3 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/naming-convention */
 export interface TeamInvite {
   team_id: string;
   invited_by: string;
@@ -12,7 +13,7 @@ export interface Failure {
 
 export interface UserTeamInfo {
   team_id: string | null;
-  role: 'leader' | 'member' | null;
+  role: TeamRole | null;
   pending_invites: TeamInvite[];
 }
 
@@ -20,7 +21,7 @@ export interface TeamDocument {
   team_id: string;
   leader_email: string;
   members: string[];
-  status: 'Active' | 'Disbanded';
+  status: TeamStatus;
   team_name: string;
   created: Date;
   updated: Date;
@@ -78,13 +79,24 @@ export interface UserDocument {
   registered_at: string;
 }
 
-type RegistrationStatus =
-  | 'unregistered'
-  | 'registered'
-  | 'rejected'
-  | 'confirmation'
-  | 'waitlist'
-  | 'coming'
-  | 'not_coming'
-  | 'confirmed'
-  | 'checked_in';
+export enum RegistrationStatus {
+  UNREGISTERED = 'unregistered',
+  REGISTERED = 'registered',
+  REJECTED = 'rejected',
+  CONFIRMATION = 'confirmation',
+  WAITLIST = 'waitlist',
+  COMING = 'coming',
+  NOT_COMING = 'not_coming',
+  CONFIRMED = 'confirmed',
+  CHECKED_IN = 'checked_in',
+}
+
+export enum TeamRole {
+  LEADER = 'leader',
+  MEMBER = 'member',
+}
+
+export enum TeamStatus {
+  ACTIVE = 'Active',
+  DISBANDED = 'Disbanded',
+}
diff --git a/tests/teams-create.test.ts b/tests/teams-create.test.ts
index a55ac54..800c4c7 100644
--- a/tests/teams-create.test.ts
+++ b/tests/teams-create.test.ts
@@ -43,6 +43,7 @@ jest.mock('../src/util', () => ({
 import { main } from '../src/functions/teams/create/handler';
 import { createEvent, mockContext } from './helper';
 import * as util from '../src/util';
+import { RegistrationStatus, TeamStatus, TeamRole } from '../src/types';
 
 describe('Teams Create Handler', () => {
   const validateTokenMock = util.validateToken as jest.Mock;
@@ -78,14 +79,14 @@ describe('Teams Create Handler', () => {
     email: 'leader@test.com',
     confirmed_team: false,
     team_info: null,
-    registration_status: 'registered',
+    registration_status: RegistrationStatus.REGISTERED,
   };
 
   const mockMemberUser = {
     email: 'member1@test.com',
     confirmed_team: false,
     team_info: null,
-    registration_status: 'registered',
+    registration_status: RegistrationStatus.REGISTERED,
   };
 
   it('should successfully create team and send invitations', async () => {
@@ -109,7 +110,7 @@ describe('Teams Create Handler', () => {
         leader_email: 'leader@test.com',
         team_name: 'Test Team',
         members: [],
-        status: 'Active',
+        status: TeamStatus.ACTIVE,
       }),
       expect.objectContaining({ session: mockSession })
     );
@@ -121,7 +122,7 @@ describe('Teams Create Handler', () => {
         $set: {
           confirmed_team: true,
           team_info: expect.objectContaining({
-            role: 'leader',
+            role: TeamRole.LEADER,
             pending_invites: [],
           }),
         },
@@ -387,7 +388,7 @@ describe('Teams Create Handler', () => {
   it('should return 400 when leader has unregistered status', async () => {
     const unregisteredLeader = {
       ...mockLeaderUser,
-      registration_status: 'unregistered',
+      registration_status: RegistrationStatus.UNREGISTERED,
     };
     mockUsersCollection.findOne.mockResolvedValue(unregisteredLeader);
 
@@ -404,7 +405,7 @@ describe('Teams Create Handler', () => {
   it('should return 400 when leader has rejected status', async () => {
     const rejectedLeader = {
       ...mockLeaderUser,
-      registration_status: 'rejected',
+      registration_status: RegistrationStatus.REJECTED,
     };
     mockUsersCollection.findOne.mockResolvedValue(rejectedLeader);
 
@@ -422,13 +423,13 @@ describe('Teams Create Handler', () => {
     const unregisteredMember = {
       ...mockMemberUser,
       email: 'member1@test.com',
-      registration_status: 'unregistered',
+      registration_status: RegistrationStatus.UNREGISTERED,
     };
 
     const waitlistMember = {
       ...mockMemberUser,
       email: 'member2@test.com',
-      registration_status: 'waitlist',
+      registration_status: RegistrationStatus.WAITLIST,
     };
 
     mockUsersCollection.findOne
@@ -443,28 +444,32 @@ describe('Teams Create Handler', () => {
     const body = JSON.parse(result.body);
     expect(body.message).toBe('Some users have invalid registration status for team creation');
     expect(body.invalid_status_users).toEqual([
-      { email: 'member1@test.com', status: 'unregistered' },
-      { email: 'member2@test.com', status: 'waitlist' },
+      { email: 'member1@test.com', status: RegistrationStatus.UNREGISTERED },
+      { email: 'member2@test.com', status: RegistrationStatus.WAITLIST },
+    ]);
+    expect(body.required_status).toEqual([
+      RegistrationStatus.REGISTERED,
+      RegistrationStatus.CONFIRMATION,
+      RegistrationStatus.COMING,
     ]);
-    expect(body.required_status).toEqual(['registered', 'confirmation', 'coming']);
   });
 
   it('should successfully create team when all users have valid registration statuses', async () => {
     const confirmationLeader = {
       ...mockLeaderUser,
-      registration_status: 'confirmation',
+      registration_status: RegistrationStatus.CONFIRMATION,
     };
 
     const comingMember = {
       ...mockMemberUser,
       email: 'member1@test.com',
-      registration_status: 'coming',
+      registration_status: RegistrationStatus.COMING,
     };
 
     const registeredMember = {
       ...mockMemberUser,
       email: 'member2@test.com',
-      registration_status: 'registered',
+      registration_status: RegistrationStatus.REGISTERED,
     };
 
     mockUsersCollection.findOne
diff --git a/tests/teams-member-removal.test.ts b/tests/teams-member-removal.test.ts
index 8d4846f..45256a5 100644
--- a/tests/teams-member-removal.test.ts
+++ b/tests/teams-member-removal.test.ts
@@ -11,7 +11,7 @@ const mockTeamsCollection = {
 
 const mockDbInstance = {
   connect: jest.fn(),
-  getCollection: jest.fn((name: string) => {
+  getCollection: jest.fn((name) => {
     if (name === 'users') return mockUsersCollection;
     if (name === 'teams') return mockTeamsCollection;
     return null;