diff --git a/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestController.java b/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestController.java
index c2796d2..def2529 100755
--- a/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestController.java
+++ b/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestController.java
@@ -2,6 +2,7 @@
 
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
 import jakarta.validation.constraints.Size;
 import lombok.RequiredArgsConstructor;
 import org.dcsa.issuance.domain.persistence.entity.enums.IssuanceRequestState;
@@ -14,6 +15,7 @@
 record ChangeStateTO(
   @NotNull
   @Size(max = 20)
+  @Pattern(regexp = "^\\S+(\\s+\\S+)*$")
   String transportDocumentReference,
 
   @NotNull
diff --git a/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestResponseController.java b/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestResponseController.java
index 6bf3b04..decb297 100755
--- a/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestResponseController.java
+++ b/issuance-application/src/main/java/org/dcsa/issuance/controller/unofficial/UnofficialIssuanceRequestResponseController.java
@@ -1,6 +1,7 @@
 package org.dcsa.issuance.controller.unofficial;
 
 import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
 import jakarta.validation.constraints.Size;
 import lombok.RequiredArgsConstructor;
 import org.dcsa.issuance.service.IssueRequestResponseService;
@@ -11,6 +12,7 @@
 record PendingIssuanceRequestResponseTO(
   @NotNull
   @Size(max = 20)
+  @Pattern(regexp = "^\\S+(\\s+\\S+)*$")
   String transportDocumentReference
 ) {
 }
diff --git a/issuance-domain/src/main/java/org/dcsa/issuance/domain/persistence/entity/IssueParty.java b/issuance-domain/src/main/java/org/dcsa/issuance/domain/persistence/entity/IssueParty.java
index 1246630..bd3a842 100755
--- a/issuance-domain/src/main/java/org/dcsa/issuance/domain/persistence/entity/IssueParty.java
+++ b/issuance-domain/src/main/java/org/dcsa/issuance/domain/persistence/entity/IssueParty.java
@@ -32,7 +32,6 @@ public class IssueParty {
   @Column(name = "location_of_registration", length = 2)
   private String locationOfRegistration;
 
-
   @Column(name = "tax_reference", length = 100)
   private String taxReference;
 
diff --git a/issuance-transfer-obj/src/main/java/org/dcsa/issuance/transferobjects/IssuanceRequestResponseTO.java b/issuance-transfer-obj/src/main/java/org/dcsa/issuance/transferobjects/IssuanceRequestResponseTO.java
index af61a2d..fbeec37 100755
--- a/issuance-transfer-obj/src/main/java/org/dcsa/issuance/transferobjects/IssuanceRequestResponseTO.java
+++ b/issuance-transfer-obj/src/main/java/org/dcsa/issuance/transferobjects/IssuanceRequestResponseTO.java
@@ -1,6 +1,7 @@
 package org.dcsa.issuance.transferobjects;
 
 import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Pattern;
 import jakarta.validation.constraints.Size;
 import lombok.Builder;
 import org.dcsa.issuance.transferobjects.enums.IssuanceResponseCodeTO;
@@ -8,10 +9,12 @@
 public record IssuanceRequestResponseTO(
   @NotNull
   @Size(max = 20)
+  @Pattern(regexp = "^\\S+(\\s+\\S+)*$")
   String transportDocumentReference,
   @NotNull
   IssuanceResponseCodeTO issuanceResponseCode,
   @Size(max = 255)
+  @Pattern(regexp = "^\\S+(\\s+\\S+)*$")
   String reason
 
 ) {