diff --git a/internal/store/mock/contact_store.go b/internal/store/mock/contact_store.go
new file mode 100644
index 0000000..f99b1b0
--- /dev/null
+++ b/internal/store/mock/contact_store.go
@@ -0,0 +1,118 @@
+package mock
+
+import (
+	"context"
+	"errors"
+	"sync"
+
+	"git.kundeng.us/phoenix/textsender-models/tx0/contact"
+	"github.com/google/uuid"
+)
+
+type Key struct {
+	PhoneNumber string
+	UserId      uuid.UUID
+}
+
+type MockContactStore struct {
+	Contacts      map[uuid.UUID]*contact.Contact
+	ContactsByKey map[Key]*contact.Contact
+	mu            sync.RWMutex
+	Error         error // Optional: simulate errors
+}
+
+func NewMockContactStore() *MockContactStore {
+	return &MockContactStore{
+		Contacts:      make(map[uuid.UUID]*contact.Contact),
+		ContactsByKey: make(map[Key]*contact.Contact),
+	}
+}
+
+func (m *MockContactStore) CreateContact(ctx context.Context, con *contact.Contact) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return m.Error
+	}
+
+	var id uuid.UUID
+	if con.Id == nil {
+		id = uuid.New()
+		con.Id = &id
+	}
+
+	key := Key{PhoneNumber: con.PhoneNumber, UserId: *con.UserId}
+	if _, exists := m.ContactsByKey[key]; exists {
+		return errors.New("Contact with phone number already exists")
+	}
+
+	m.Contacts[*con.Id] = con
+	m.ContactsByKey[key] = con
+	return nil
+}
+
+func (m *MockContactStore) GetContactByID(ctx context.Context, id uuid.UUID) (*contact.Contact, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return nil, m.Error
+	}
+
+	if m.Error != nil {
+		return nil, m.Error
+	}
+
+	con, exists := m.Contacts[id]
+	if !exists {
+		return nil, errors.New("Contact not found")
+	}
+
+	return con, nil
+}
+
+func (m *MockContactStore) GetContactByPhone(ctx context.Context, phoneNumber string, userId uuid.UUID) (*contact.Contact, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return nil, m.Error
+	}
+
+	con, exists := m.ContactsByKey[Key{PhoneNumber: phoneNumber, UserId: userId}]
+	if !exists {
+		return nil, errors.New("Contact not found")
+	}
+
+	return con, nil
+}
+
+func (m *MockContactStore) GetAllContacts(ctx context.Context) ([]*contact.Contact, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return nil, m.Error
+	}
+
+	cons := make([]*contact.Contact, 0, len(m.Contacts))
+	for _, con := range m.Contacts {
+		cons = append(cons, con)
+	}
+
+	return cons, nil
+}
+
+func (m *MockContactStore) ContactExists(ctx context.Context, phoneNumber string, userId uuid.UUID) (bool, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return false, m.Error
+	}
+
+	_, exists := m.ContactsByKey[Key{PhoneNumber: phoneNumber, UserId: userId}]
+
+	return exists, nil
+}