diff --git a/Elwig/Documents/BusinessDocument.cs b/Elwig/Documents/BusinessDocument.cs
index b09108a..3399758 100644
--- a/Elwig/Documents/BusinessDocument.cs
+++ b/Elwig/Documents/BusinessDocument.cs
@@ -30,7 +30,7 @@ namespace Elwig.Documents {
             get {
                 IAddress addr = (Member.BillingAddress != null && UseBillingAddress) ? Member.BillingAddress : Member;
                 var plz = addr.PostalDest.AtPlz;
-                return string.Join("\n", ((string?[])[Member.BillingAddress?.FullName, Member.AdministrativeName, Member.ForTheAttentionOf, addr.Address, $"{plz?.Plz} {plz?.Ort.Name.Split(",")[0]}", addr.PostalDest.Country.Name]).Where(s => !string.IsNullOrWhiteSpace(s)));
+                return string.Join("\n", ((string?[])[addr is BillingAddr ? addr.FullName : null, Member.AdministrativeName, Member.ForTheAttentionOf, addr.Address, $"{plz?.Plz} {plz?.Ort.Name.Split(",")[0]}", addr.PostalDest.Country.Name]).Where(s => !string.IsNullOrWhiteSpace(s)));
             }
         }