diff --git a/client/models.py b/client/models.py
index 85eafbd..c8c6b76 100644
--- a/client/models.py
+++ b/client/models.py
@@ -1,8 +1,45 @@
 from django.db import models
 
 
+class TaxType(models.Model):
+    name = models.CharField(max_length=15)
+    percentage = models.DecimalField()
+
+    def __str__(self):
+        return self.name
+
+
+class Country(models.Model):
+    name = models.CharField(max_length=30)
+
+    def __str__(self):
+        return self.name
+
+
+class State(models.Model):
+    name = models.CharField(max_length=30)
+    country = models.OneToOneField(Country, on_delete=models.CASCADE)
+
+    def __str__(self):
+        return self.name
+
+
+class City(models.Model):
+    name = models.CharField(max_length=30)
+    state = models.OneToOneField(State, on_delete=models.CASCADE)
+
+    def __str__(self):
+        return self.name
+
+
 class Client(models.Model):
     name = models.CharField(max_length=30)
+    profile_picture = models.ImageField(upload_to='client_images', null=True, blank=True)
+    city = models.ForeignKey(City, on_delete=models.CASCADE)
+    address_line1 = models.CharField(max_length=50)
+    address_line2 = models.CharField(max_length=50)
+    postal_code = models.CharField(max_length=15)
+    tax_type = models.ForeignKey(TaxType, on_delete=models.CASCADE)
     tax_id = models.CharField(max_length=30)
 
     def __str__(self):
diff --git a/employee/models.py b/employee/models.py
index 405a8b7..817bd9e 100644
--- a/employee/models.py
+++ b/employee/models.py
@@ -1,16 +1,17 @@
 from django.contrib.auth.models import User
 from django.db import models
+from phonenumber_field.modelfields import PhoneNumberField
 from project.models import Project
 
 
 class Employee(models.Model):
-    user = models.ForeignKey(User)
-    phone = models.CharField(max_length=15)
-    salary = models.FloatField()
-    emp_id = models.CharField(max_length=15)
+    user = models.OneToOneField(User, on_delete=models.CASCADE)
+    employee_id = models.CharField(max_length=15)
+    phone = PhoneNumberField()
+    salary = models.DecimalField()
     start_date = models.DateField()
     end_date = models.DateField(null=True, blank=True)
     projects = models.ManyToManyField(Project)
 
     def __str__(self):
-        return self.name
+        return self.user.name
diff --git a/invoice/models.py b/invoice/models.py
index a3624c1..103ffca 100644
--- a/invoice/models.py
+++ b/invoice/models.py
@@ -3,11 +3,22 @@ from project.models import Project
 
 
 class Invoice(models.Model):
-    project = models.ForeignKey(Project)
+    project = models.ForeignKey(Project, on_delete=models.CASCADE)
     invoice_id = models.CharField(max_length=15)
     raised_date = models.DateField()
     due_date = models.DateField()
-    is_paid = models.BooleanField()
+    paid_date = models.DateField(null=True, blank=True)
+    is_archived = models.BooleanField()
 
     def __str__(self):
         return self.invoice_id
+
+
+class Item(models.Model):
+    name = models.TextField(blank=False, null=False)
+    amount = models.DecimalField()
+    quantity = models.IntegerField()
+    invoice = models.OneToOneField(Invoice, on_delete=models.CASCADE)
+
+    def __str__(self):
+        return self.name
diff --git a/project/models.py b/project/models.py
index d1996a3..fab9b28 100644
--- a/project/models.py
+++ b/project/models.py
@@ -4,8 +4,11 @@ from client.models import Client
 
 class Project(models.Model):
     name = models.CharField(max_length=30)
-    price = models.FloatField()
-    client = models.ForeignKey(Client)
+    project_image = models.ImageField(upload_to='project_images', null=True, blank=True)
+    client = models.ForeignKey(Client, on_delete=models.CASCADE)
+    total_cost = models.DecimalField()
+    start_date = models.DateField()
+    end_date = models.DateField()
 
     def __str__(self):
         return self.name
diff --git a/representative/models.py b/representative/models.py
index 1fc98f1..f288a0f 100644
--- a/representative/models.py
+++ b/representative/models.py
@@ -1,15 +1,23 @@
 from django.contrib.auth.models import User
 from django.db import models
+from phonenumber_field.modelfields import PhoneNumberField
 from project.models import Project
 from client.models import Client
 
 
+class Role(models.Model):
+    name = models.CharField(max_length=30)
+
+    def __str__(self):
+        return self.name
+
+
 class Representative(models.Model):
-    user = models.ForeignKey(User)
-    phone = models.CharField(max_length=15)
-    role = models.CharField(max_length=15)
+    user = models.OneToOneField(User, on_delete=models.CASCADE)
+    phone = PhoneNumberField()
+    role = models.ForeignKey(Role, on_delete=models.CASCADE)
     projects = models.ManyToManyField(Project)
-    clients = models.ManyToManyField(Client)
+    clients = models.ForeignKey(Client, on_delete=models.CASCADE)
 
     def __str__(self):
         return self.user.name
diff --git a/workx_backend/settings/base.py b/workx_backend/settings/base.py
index b56f11a..74f05a5 100644
--- a/workx_backend/settings/base.py
+++ b/workx_backend/settings/base.py
@@ -24,6 +24,7 @@ INSTALLED_APPS = [
     'rest_framework.authtoken',
     'drfpasswordless',
     'drf_yasg',
+    'phonenumber_field',
     'client',
     'employee',
     'invoice',