title: Compare two lists with Except method
body: <p>I'm trying to compare two lists with the Except method but it doesn't work correct:</p>
  
  <pre><code>List&lt;Customer&gt; PotentialSharedCustomer = new List&lt;Customer&gt;();
  PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "01234", Name = "Hans Jürgen" });
  PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "05465", Name = "Beate Müller" });
  PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "15645", Name = "Sabine Meyer" });
  PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "54654", Name = "Moritz Kummerfeld" });
  PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "15647", Name = "Hanna Testname" });
  
  List&lt;Customer&gt; ActualSharedCustomer = new List&lt;Customer&gt;();
  ActualSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "01234", Name = "Hans Jürgen" });
  ActualSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "05465", Name = "Beate Müller" });
  ActualSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "15645", Name = "Sabine Meyer" });
  
  PrepareCreateSharedCustomer(PotentialSharedCustomer, ActualSharedCustomer);
  
  public void PrepareCreateSharedCustomer(List&lt;Customer&gt; potentialSharedCustomer, List&lt;Customer&gt; actualSharedCustomer)
  {
      List&lt;Customer&gt; result = potentialSharedCustomer.Except(actualSharedCustomer).ToList&lt;Customer&gt;();
  }
  </code></pre>
  
  <p>The result of the variable "result" should be all records of "PotentialSharedCustomers", there are not in the list "ActialSharedCustomer":</p>
  
  <pre><code>PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "54654", Name = "Moritz Kummerfeld" });
  PotentialSharedCustomer.Add(new Customer { AccountId = Guid.Empty, AccountNumber = "15647", Name = "Hanna Testname" });
  </code></pre>
  
  <p>I thougt "Except" is the correct way to solve this, but I get the return of all items of "PotentialSharedCustomer"</p>
  
  <p>Thx for help</p>