diff --git a/classes/Modules/Address/www/js/address_create.js b/classes/Modules/Address/www/js/address_create.js
index aec7149ed..099b7f110 100644
--- a/classes/Modules/Address/www/js/address_create.js
+++ b/classes/Modules/Address/www/js/address_create.js
@@ -10,6 +10,7 @@ var AddressDuplicates = (function ($) {
         },
 
         init: function () {
+            me.registerZipcodeSanitizer();
             me.registerEvents();
         },
 
@@ -33,6 +34,40 @@ var AddressDuplicates = (function ($) {
             });
         },
 
+        registerZipcodeSanitizer: function () {
+            var $zipcodeFields = $('#plz, #rechnung_plz');
+
+            if(!$zipcodeFields.length){
+                return;
+            }
+
+            me.sanitizeZipcodeField($zipcodeFields);
+
+            $zipcodeFields.on('blur change', function () {
+                me.sanitizeZipcodeField($(this));
+            });
+        },
+
+        sanitizeZipcodeField: function ($field) {
+            if(!$field || !$field.length){
+                return;
+            }
+
+            $field.each(function () {
+                var $currentField = $(this);
+                var currentValue = $currentField.val();
+                if(typeof currentValue !== 'string'){
+                    return;
+                }
+
+                // Entfernt Leerzeichen am Anfang oder Ende, die keine eigentlichen Zeichen flankieren
+                var sanitizedValue = currentValue.replace(/^\s+|\s+$/g, '');
+                if(sanitizedValue !== currentValue){
+                    $currentField.val(sanitizedValue);
+                }
+            });
+        },
+
         checkDuplicate: function () {
             var nameValue = $('#name').val();
             var streetValue = $('#strasse').val();
@@ -58,4 +93,4 @@ var AddressDuplicates = (function ($) {
 
 $(document).ready(function () {
     AddressDuplicates.init();
-});
\ No newline at end of file
+});
diff --git a/package.json b/package.json
index 869f8afc8..53d2cb3a6 100644
--- a/package.json
+++ b/package.json
@@ -6,6 +6,7 @@
     "api-docs:build": "./node_modules/raml2html/bin/raml2html --validate --theme raml2html-werk-theme --input www/api/docs.raml --output www/api/docs-tmp.html && cat www/api/docs-tmp.html | sed -e 's/<\\/head>/<link rel=\\\"stylesheet\\\" href=\\\"\\.\\/assets\\/docs_custom\\.css\\\"><\\/head>/' > www/api/docs.html && rm www/api/docs-tmp.html",
     "dev": "vite -d --cors --host ::",
     "build": "vite build",
+    "test:zipcode": "node --test tests/address_zipcode_sanitizer.test.js",
     "preview": "vite preview"
   },
   "devDependencies": {
diff --git a/tests/address_zipcode_sanitizer.test.js b/tests/address_zipcode_sanitizer.test.js
new file mode 100644
index 000000000..1ec3f8e0c
--- /dev/null
+++ b/tests/address_zipcode_sanitizer.test.js
@@ -0,0 +1,172 @@
+import assert from 'node:assert';
+import fs from 'node:fs';
+import path from 'node:path';
+import {fileURLToPath} from 'node:url';
+import vm from 'node:vm';
+import test from 'node:test';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const scriptPath = path.resolve(__dirname, '..', 'classes', 'Modules', 'Address', 'www', 'js', 'address_create.js');
+
+const createElement = (id, value = '') => ({
+  id,
+  value,
+  handlers: {},
+  classes: new Set(),
+});
+
+const createJQueryStub = (elements, documentElement) => {
+  function JQueryCollection(resolvedElements) {
+    this.elements = resolvedElements;
+    this.length = resolvedElements.length;
+  }
+
+  JQueryCollection.prototype.on = function (events, handler) {
+    const eventList = events.split(/\s+/);
+    this.elements.forEach((element) => {
+      eventList.forEach((evt) => {
+        if (!element.handlers[evt]) {
+          element.handlers[evt] = [];
+        }
+        element.handlers[evt].push(handler);
+      });
+    });
+    return this;
+  };
+
+  JQueryCollection.prototype.ready = function (handler) {
+    if (typeof handler === 'function') {
+      handler();
+    }
+    return this;
+  };
+
+  JQueryCollection.prototype.val = function (newValue) {
+    if (newValue === undefined) {
+      return this.elements[0]?.value;
+    }
+    this.elements.forEach((element) => {
+      element.value = newValue;
+    });
+    return this;
+  };
+
+  JQueryCollection.prototype.each = function (callback) {
+    this.elements.forEach((element, index) => {
+      callback.call(element, index, element);
+    });
+    return this;
+  };
+
+  JQueryCollection.prototype.trigger = function (eventName) {
+    this.elements.forEach((element) => {
+      const handlers = element.handlers[eventName] || [];
+      handlers.forEach((handler) => handler.call(element, {type: eventName}));
+    });
+    return this;
+  };
+
+  JQueryCollection.prototype.addClass = function (className) {
+    this.elements.forEach((element) => element.classes.add(className));
+    return this;
+  };
+
+  JQueryCollection.prototype.removeClass = function (className) {
+    this.elements.forEach((element) => element.classes.delete(className));
+    return this;
+  };
+
+  JQueryCollection.prototype.hasClass = function (className) {
+    return this.elements.some((element) => element.classes.has(className));
+  };
+
+  JQueryCollection.prototype.next = function () {
+    return {
+      remove: () => undefined,
+    };
+  };
+
+  JQueryCollection.prototype.insertAfter = function () {
+    return this;
+  };
+
+  JQueryCollection.prototype.html = function () {
+    return this;
+  };
+
+  const resolveSelector = (selector) => {
+    if (selector === document || selector === 'document') {
+      return [documentElement];
+    }
+
+    if (typeof selector === 'string') {
+      if (selector.startsWith('<')) {
+        return [createElement('generated')];
+      }
+      const ids = selector.split(',').map((part) => part.trim());
+      return ids
+        .map((id) => (id.startsWith('#') ? id : `#${id}`))
+        .map((id) => elements[id])
+        .filter(Boolean);
+    }
+
+    if (selector && selector.id && elements[`#${selector.id}`]) {
+      return [elements[`#${selector.id}`]];
+    }
+
+    return [];
+  };
+
+  const jQuery = function (selector) {
+    return new JQueryCollection(resolveSelector(selector));
+  };
+
+  jQuery.ajax = () => ({
+    done: (handler) => {
+      handler(false);
+      return this;
+    },
+  });
+
+  return jQuery;
+};
+
+const setupEnvironment = (plzValue, rechnungPlzValue) => {
+  const elements = {
+    '#plz': createElement('plz', plzValue),
+    '#rechnung_plz': createElement('rechnung_plz', rechnungPlzValue),
+    '#name': createElement('name'),
+    '#strasse': createElement('strasse'),
+    '#ort': createElement('ort'),
+  };
+
+  const documentElement = createElement('document');
+  const $ = createJQueryStub(elements, documentElement);
+
+  globalThis.$ = $;
+  globalThis.jQuery = $;
+  globalThis.document = documentElement;
+
+  const scriptContent = fs.readFileSync(scriptPath, 'utf8');
+  vm.runInThisContext(scriptContent, {filename: scriptPath});
+
+  return {elements, $};
+};
+
+test('sanitizes zipcode fields on init', () => {
+  const {elements} = setupEnvironment(' 12345 ', ' 98765 ');
+
+  assert.equal(elements['#plz'].value, '12345');
+  assert.equal(elements['#rechnung_plz'].value, '98765');
+});
+
+test('sanitizes zipcode fields on blur', () => {
+  const {elements, $} = setupEnvironment('12345 ', '98765 ');
+
+  $(elements['#plz']).val(' 54321 ').trigger('blur');
+  $(elements['#rechnung_plz']).val(' 56789 ').trigger('blur');
+
+  assert.equal(elements['#plz'].value, '54321');
+  assert.equal(elements['#rechnung_plz'].value, '56789');
+});