diff --git a/src/main/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidator.java b/src/main/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidator.java
index 3d62b765..c9fd731a 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidator.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidator.java
@@ -25,8 +25,9 @@ class HsDomainSetupBookingItemValidator extends HsBookingItemEntityValidator {
                         .notMatchesRegEx(REGISTRAR_LEVEL_DOMAINS).describedAs("is a forbidden registrar-level domain name")
                         .required(),
                 stringProperty(VERIFICATION_CODE_PROPERTY_NAME)
-                        .readOnly().initializedBy(HsDomainSetupBookingItemValidator::generateVerificationCode)
-
+                        .minLength(12)
+                        .maxLength(64)
+                        .initializedBy(HsDomainSetupBookingItemValidator::generateVerificationCode)
         );
     }
 
diff --git a/src/main/java/net/hostsharing/hsadminng/hs/validation/ValidatableProperty.java b/src/main/java/net/hostsharing/hsadminng/hs/validation/ValidatableProperty.java
index d0966a5e..fb51e7fe 100644
--- a/src/main/java/net/hostsharing/hsadminng/hs/validation/ValidatableProperty.java
+++ b/src/main/java/net/hostsharing/hsadminng/hs/validation/ValidatableProperty.java
@@ -266,7 +266,7 @@ public abstract class ValidatableProperty<P extends ValidatableProperty<?, ?>, T
 
     private boolean isSpecPotentiallyComplete() {
         return required == null && requiresAtLeastOneOf == null && requiresAtMaxOneOf == null && !readOnly && !writeOnly
-                && defaultValue == null;
+                && defaultValue == null && computedBy == null;
     }
 
     @SuppressWarnings("unchecked")
diff --git a/src/test/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidatorUnitTest.java b/src/test/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidatorUnitTest.java
index 9fbdac45..643c5e54 100644
--- a/src/test/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidatorUnitTest.java
+++ b/src/test/java/net/hostsharing/hsadminng/hs/booking/item/validators/HsDomainSetupBookingItemValidatorUnitTest.java
@@ -28,7 +28,7 @@ class HsDomainSetupBookingItemValidatorUnitTest {
     private EntityManager em;
 
     @Test
-    void acceptsRegisterableDomain() {
+    void acceptsRegisterableDomainWithGeneratedVerificationCode() {
         // given
         final var domainSetupBookingItemEntity = HsBookingItemRealEntity.builder()
                 .type(DOMAIN_SETUP)
@@ -46,6 +46,26 @@ class HsDomainSetupBookingItemValidatorUnitTest {
         assertThat(result).isEmpty();
     }
 
+    @Test
+    void acceptsRegisterableDomainWithExplicitVerifiactionCode() {
+        // given
+        final var domainSetupBookingItemEntity = HsBookingItemRealEntity.builder()
+                .type(DOMAIN_SETUP)
+                .project(project)
+                .caption("Test-Domain")
+                .resources(Map.ofEntries(
+                        entry("domainName", "example.org"),
+                        entry("verificationCode", "1234-5678-9100")
+                ))
+                .build();
+
+        // when
+        final var result = HsBookingItemEntityValidatorRegistry.doValidate(em, domainSetupBookingItemEntity);
+
+        // then
+        assertThat(result).isEmpty();
+    }
+
     @Test
     void acceptsMaximumDomainNameLength() {
         final var domainSetupBookingItemEntity = HsBookingItemRealEntity.builder()
@@ -150,6 +170,6 @@ class HsDomainSetupBookingItemValidatorUnitTest {
         // then
         assertThat(validator.properties()).map(Map::toString).containsExactlyInAnyOrder(
                 "{type=string, propertyName=domainName, matchesRegEx=[^((?!-)[A-Za-z0-9-]{1,63}(?<!-)\\.)+[A-Za-z]{2,12}], matchesRegExDescription=is not a (non-top-level) fully qualified domain name, notMatchesRegEx=[[^.]+, (co|org|gov|ac|sch)\\.uk, (com|net|org|edu|gov|asn|id)\\.au, (co|ne|or|ac|go)\\.jp, (com|net|org|gov|edu|ac)\\.cn, (com|net|org|gov|edu|mil|art)\\.br, (co|net|org|gen|firm|ind)\\.in, (com|net|org|gob|edu)\\.mx, (gov|edu)\\.it, (co|net|org|govt|ac|school|geek|kiwi)\\.nz, (co|ne|or|go|re|pe)\\.kr], notMatchesRegExDescription=is a forbidden registrar-level domain name, maxLength=253, required=true, writeOnce=true}",
-                "{type=string, propertyName=verificationCode, readOnly=true, computed=IN_INIT}");
+                "{type=string, propertyName=verificationCode, minLength=12, maxLength=64, computed=IN_INIT}");
     }
 }