diff --git a/app/models/rate.rb b/app/models/rate.rb
index 71b0283..bbe0347 100644
--- a/app/models/rate.rb
+++ b/app/models/rate.rb
@@ -13,4 +13,7 @@ class Rate < ActiveRecord::Base
     }
   }
 
+  def locked?
+    return self.time_entries.length > 0
+  end
 end
diff --git a/spec/models/rate_spec.rb b/spec/models/rate_spec.rb
index 653c9c1..6601601 100644
--- a/spec/models/rate_spec.rb
+++ b/spec/models/rate_spec.rb
@@ -57,3 +57,16 @@ describe Rate, 'associations' do
 
 end
 
+describe Rate, 'locked?' do
+  it 'should be true if a Time Entry is associated' do
+    rate = Rate.new
+    rate.time_entries << mock_model(TimeEntry)
+    rate.locked?.should be_true
+  end
+  
+  it 'should be false if no Time Entries are associated' do
+    rate = Rate.new
+    rate.locked?.should be_false
+  end
+  
+end