diff --git a/lib/postnord.rb b/lib/postnord.rb
index e5f25fb..85eea2f 100644
--- a/lib/postnord.rb
+++ b/lib/postnord.rb
@@ -3,11 +3,11 @@
 require 'net/https'
 require 'json'
 require 'openssl'
-require 'byebug'
 
 require 'postnord/client'
 require 'postnord/response'
 require 'postnord/base'
+require 'postnord/business_location'
 require 'postnord/shipment'
 require 'postnord/transport'
 require 'postnord/version'
diff --git a/lib/postnord/business_location.rb b/lib/postnord/business_location.rb
index da372a4..6760853 100644
--- a/lib/postnord/business_location.rb
+++ b/lib/postnord/business_location.rb
@@ -2,7 +2,7 @@ module Postnord
 
   # Classes
 
-  class BusinessLocation
+  class BusinessLocation < Base
     def self.service
       'businesslocation'
     end
diff --git a/spec/postnord/base_spec.rb b/spec/postnord/base_spec.rb
new file mode 100644
index 0000000..e66f453
--- /dev/null
+++ b/spec/postnord/base_spec.rb
@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+RSpec.describe Postnord::Base do
+  describe '.mandatory_params' do
+    it 'raises not implemented error' do
+      expect {
+        described_class.send(:mandatory_params)
+      }.to raise_error(NotImplementedError, 'mandatory_params')
+    end
+  end
+
+  describe '.endpoint' do
+    it 'raises not implemented error' do
+      expect {
+        described_class.send(:endpoint)
+      }.to raise_error(NotImplementedError, 'endpoint')
+    end
+  end
+
+  describe '.validate_params' do
+    before do
+      expect(described_class).to receive(:mandatory_params).and_return(['param1', 'param2'])
+    end
+
+    context 'with missing param' do
+      it 'raises missing mandatory parameters error' do
+        expect {
+          described_class.send(:validate_params, { param1: 'test' })
+        }.to raise_error(Postnord::Base::MissingMandatoryParameters, /param2/)
+      end
+    end
+
+    context 'without missing param' do
+      it 'does not raise any error' do
+        expect {
+          described_class.send(:validate_params, { param1: 'test', param2: 'test' })
+        }.not_to raise_error(Postnord::Base::MissingMandatoryParameters)
+      end
+    end
+  end
+end
diff --git a/spec/postnord/business_location_spec.rb b/spec/postnord/business_location_spec.rb
new file mode 100644
index 0000000..182a41f
--- /dev/null
+++ b/spec/postnord/business_location_spec.rb
@@ -0,0 +1,41 @@
+require 'spec_helper'
+
+RSpec.describe Postnord::BusinessLocation do
+  describe '.service' do
+    it 'uses correct service' do
+      expect(described_class.service).to eq 'businesslocation'
+    end
+  end
+end
+
+RSpec.describe Postnord::FindNearestByCoordinates do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'servicepoint/findNearestByCoordinates'
+    end
+  end
+end
+
+RSpec.describe Postnord::FindByPostalCode do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'servicepoint/findByPostalCode'
+    end
+  end
+end
+
+RSpec.describe Postnord::FindNearestByAddress do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'servicepoint/findNearestByAddress'
+    end
+  end
+end
+
+RSpec.describe Postnord::GetServicePointInformation do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'servicepoint/getServicePointInformation'
+    end
+  end
+end
diff --git a/spec/postnord/shipment_spec.rb b/spec/postnord/shipment_spec.rb
new file mode 100644
index 0000000..7671ea8
--- /dev/null
+++ b/spec/postnord/shipment_spec.rb
@@ -0,0 +1,33 @@
+require 'spec_helper'
+
+RSpec.describe Postnord::Shipment do
+  describe '.service' do
+    it 'uses correct service' do
+      expect(described_class.service).to eq 'shipment'
+    end
+  end
+end
+
+RSpec.describe Postnord::FindByIdentifier do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'trackandtrace/findByIdentifier'
+    end
+  end
+end
+
+RSpec.describe Postnord::FindByNotificationCode do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'trackandtrace/findByNotificationCode'
+    end
+  end
+end
+
+RSpec.describe Postnord::FindByReference do
+  describe '.endpoint' do
+    it 'calls correct endpoint' do
+      expect(described_class.endpoint).to eq 'trackandtrace/findByReference'
+    end
+  end
+end
diff --git a/spec/postnord/transport_spec.rb b/spec/postnord/transport_spec.rb
new file mode 100644
index 0000000..5e2889c
--- /dev/null
+++ b/spec/postnord/transport_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+RSpec.describe Postnord::Transport do
+  describe '.service' do
+    it 'uses correct service' do
+      expect(described_class.service).to eq 'transport'
+    end
+  end
+end
+
+RSpec.describe Postnord::GetTransitTimeInformation do
+  describe '.endpoint' do
+    it 'calls endpoint' do
+      expect(described_class.endpoint).to eq 'transittime/getTransitTimeInformation'
+    end
+  end
+end
diff --git a/spec/postnord_spec.rb b/spec/postnord_spec.rb
index 5195758..de9695a 100644
--- a/spec/postnord_spec.rb
+++ b/spec/postnord_spec.rb
@@ -5,7 +5,49 @@
     expect(Postnord::VERSION).not_to be nil
   end
 
-  it 'does something useful' do
-    expect(false).to eq(true)
+  describe '.find_by_identifier' do
+    let(:id) { '123' }
+
+    before do
+      expect(Postnord::FindByIdentifier).to receive(:call).with({
+        id: id,
+      })
+    end
+
+    it 'calls FindByIdentifier with correct params' do
+      described_class.find_by_identifier(id)
+    end
+  end
+
+  describe '.find_by_notification_code' do
+    let(:phone_number) { '0701112233' }
+    let(:notification_code) { '123' }
+
+    before do
+      expect(Postnord::FindByNotificationCode).to receive(:call).with({
+        notificationPhoneNumber: phone_number,
+        notificationCode: notification_code,
+      })
+    end
+
+    it 'calls FindByNotificationCode with correct params' do
+      described_class.find_by_notification_code(phone_number, notification_code)
+    end
+  end
+
+  describe '.find_by_reference' do
+    let(:customer_number) { '123' }
+    let(:reference_value) { '456' }
+
+    before do
+      expect(Postnord::FindByReference).to receive(:call).with({
+        customerNumber: customer_number,
+        referenceValue: reference_value,
+      })
+    end
+
+    it 'calls FindByReference with correct params' do
+      described_class.find_by_reference(customer_number, reference_value)
+    end
   end
 end