diff --git a/Elwig/Documents/BusinessDocument.cshtml.cs b/Elwig/Documents/BusinessDocument.cshtml.cs
index 1cee709..62cd759 100644
--- a/Elwig/Documents/BusinessDocument.cshtml.cs
+++ b/Elwig/Documents/BusinessDocument.cshtml.cs
@@ -12,7 +12,7 @@ namespace Elwig.Documents {
             Member = m;
             Location = App.BranchName;
             IncludeSender = includeSender;
-            var uid = (m.UstId ?? "-") + (m.IsBuchführend ? "" : " <i>(pauschaliert)</i>");
+            var uid = (m.UstIdNr ?? "-") + (m.IsBuchführend ? "" : " <i>(pauschaliert)</i>");
             Aside = $"<table><colgroup><col span='1' style='width: 2.25cm;'/><col span='1' style='width: 100%;'/></colgroup>" +
                 $"<thead><tr><th colspan='2'>Mitglied</th></tr></thead><tbody>" +
                 $"<tr><th>Mitglieds-Nr.</th><td>{m.MgNr}</td></tr>" +
diff --git a/Elwig/Documents/Document.cshtml.cs b/Elwig/Documents/Document.cshtml.cs
index 26f02c8..e4a307e 100644
--- a/Elwig/Documents/Document.cshtml.cs
+++ b/Elwig/Documents/Document.cshtml.cs
@@ -17,7 +17,7 @@ namespace Elwig.Documents {
             Footer = Utils.GenerateFooter("<br/>", " \u00b7 ")
                 .Item(c.NameFull).NextLine()
                 .Item(c.Address).Item($"{c.Plz} {c.Ort}").Item("Österreich").Item("Tel.", c.PhoneNr).Item("Fax", c.FaxNr).NextLine()
-                .Item(c.EmailAddress).Item(c.Website).Item("Betriebs-Nr.", c.LfbisNr).Item("UID", c.UstId).NextLine()
+                .Item(c.EmailAddress).Item(c.Website).Item("Betriebs-Nr.", c.LfbisNr).Item("UID", c.UstIdNr).NextLine()
                 .Item("BIC", c.Bic).Item("IBAN", c.Iban)
                 .ToString();
             Date = DateTime.Today;
diff --git a/Elwig/Helpers/ClientParameters.cs b/Elwig/Helpers/ClientParameters.cs
index 958baac..8a1d005 100644
--- a/Elwig/Helpers/ClientParameters.cs
+++ b/Elwig/Helpers/ClientParameters.cs
@@ -30,7 +30,7 @@ namespace Elwig.Helpers {
 
         public string? Iban;
         public string? Bic;
-        public string? UstId;
+        public string? UstIdNr;
         public string? LfbisNr;
 
         public string? PhoneNr;
@@ -66,7 +66,7 @@ namespace Elwig.Helpers {
                 EmailAddress = parameters.GetValueOrDefault("CLIENT_EMAIL");
                 Website = parameters.GetValueOrDefault("CLIENT_WEBSITE");
                 LfbisNr = parameters.GetValueOrDefault("CLIENT_LFBISNR");
-                UstId = parameters.GetValueOrDefault("CLIENT_USTIDNR");
+                UstIdNr = parameters.GetValueOrDefault("CLIENT_USTIDNR");
                 Bic = parameters.GetValueOrDefault("CLIENT_BIC");
                 Iban = parameters.GetValueOrDefault("CLIENT_IBAN");
                 Sender2 = parameters.GetValueOrDefault("DOCUMENT_SENDER") ?? "";
diff --git a/Elwig/Helpers/Validator.cs b/Elwig/Helpers/Validator.cs
index 2ed59c2..e40f9cd 100644
--- a/Elwig/Helpers/Validator.cs
+++ b/Elwig/Helpers/Validator.cs
@@ -332,7 +332,7 @@ namespace Elwig.Helpers {
             return new(true, null);
         }
 
-        public static ValidationResult CheckUstId(TextBox input, bool required) {
+        public static ValidationResult CheckUstIdNr(TextBox input, bool required) {
             string text = "";
             int pos = input.CaretIndex;
             for (int i = 0, v = 0; i < input.Text.Length; i++) {
diff --git a/Elwig/Models/Member.cs b/Elwig/Models/Member.cs
index 675331a..c021a51 100644
--- a/Elwig/Models/Member.cs
+++ b/Elwig/Models/Member.cs
@@ -95,8 +95,8 @@ namespace Elwig.Models {
         [Column("lfbis_nr")]
         public string? LfbisNr { get; set; }
 
-        [Column("ustid")]
-        public string? UstId { get; set; }
+        [Column("ustid_nr")]
+        public string? UstIdNr { get; set; }
 
         [Column("volllieferant")]
         public bool IsVollLieferant { get; set; }
diff --git a/Elwig/Windows/AdministrationWindow.cs b/Elwig/Windows/AdministrationWindow.cs
index 11e4e79..44a7f21 100644
--- a/Elwig/Windows/AdministrationWindow.cs
+++ b/Elwig/Windows/AdministrationWindow.cs
@@ -422,12 +422,12 @@ namespace Elwig.Windows {
             InputLostFocus((TextBox)sender, Validator.CheckBic);
         }
 
-        protected void UstIdInput_TextChanged(object sender, RoutedEventArgs evt) {
-            InputTextChanged((TextBox)sender, Validator.CheckUstId);
+        protected void UstIdNrInput_TextChanged(object sender, RoutedEventArgs evt) {
+            InputTextChanged((TextBox)sender, Validator.CheckUstIdNr);
         }
 
-        protected void UstIdInput_LostFocus(object sender, RoutedEventArgs evt) {
-            InputLostFocus((TextBox)sender, Validator.CheckUstId);
+        protected void UstIdNrInput_LostFocus(object sender, RoutedEventArgs evt) {
+            InputLostFocus((TextBox)sender, Validator.CheckUstIdNr);
         }
 
         protected void LfbisNrInput_TextChanged(object sender, RoutedEventArgs evt) {
diff --git a/Elwig/Windows/MemberAdminWindow.xaml b/Elwig/Windows/MemberAdminWindow.xaml
index aa9b346..19c9c3a 100644
--- a/Elwig/Windows/MemberAdminWindow.xaml
+++ b/Elwig/Windows/MemberAdminWindow.xaml
@@ -258,8 +258,8 @@
                 </Grid.ColumnDefinitions>
 
                 <Label Content="UID:" Margin="10,10,0,0" Grid.Column="0"/>
-                <TextBox x:Name="UstIdInput" Margin="0,10,10,0" Grid.Column="1" Width="120" HorizontalAlignment="Left"
-                         TextChanged="UstIdInput_TextChanged" LostFocus="UstIdInput_LostFocus"/>
+                <TextBox x:Name="UstIdNrInput" Margin="0,10,10,0" Grid.Column="1" Width="120" HorizontalAlignment="Left"
+                         TextChanged="UstIdNrInput_TextChanged" LostFocus="UstIdNrInput_LostFocus"/>
 
                 <Label Content="BetriebsNr.:" Margin="10,40,0,0" Grid.Column="0"/>
                 <TextBox x:Name="LfbisNrInput" Margin="0,40,10,0" Grid.Column="1" Width="64" HorizontalAlignment="Left" TextAlignment="Right"
diff --git a/Elwig/Windows/MemberAdminWindow.xaml.cs b/Elwig/Windows/MemberAdminWindow.xaml.cs
index 96905e4..7d0b0cc 100644
--- a/Elwig/Windows/MemberAdminWindow.xaml.cs
+++ b/Elwig/Windows/MemberAdminWindow.xaml.cs
@@ -346,7 +346,7 @@ namespace Elwig.Windows {
             m.Iban = (IbanInput.Text == "") ? null : IbanInput.Text.Replace(" ", "");
             m.Bic = (BicInput.Text == "") ? null : BicInput.Text;
 
-            m.UstId = (UstIdInput.Text == "") ? null : UstIdInput.Text;
+            m.UstIdNr = (UstIdNrInput.Text == "") ? null : UstIdNrInput.Text;
             m.LfbisNr = (LfbisNrInput.Text == "") ? null : LfbisNrInput.Text;
             m.IsBuchführend = BuchführendInput.IsChecked ?? false;
 
@@ -476,7 +476,7 @@ namespace Elwig.Windows {
             IbanInput.Text = m.Iban;
             BicInput.Text = m.Bic;
 
-            UstIdInput.Text = m.UstId;
+            UstIdNrInput.Text = m.UstIdNr;
             LfbisNrInput.Text = m.LfbisNr;
             BuchführendInput.IsChecked = m.IsBuchführend;