diff --git a/frontend/src/modules/member/components/list/member-list-toolbar.vue b/frontend/src/modules/member/components/list/member-list-toolbar.vue
index 7ab2eeaea0..40e331040e 100644
--- a/frontend/src/modules/member/components/list/member-list-toolbar.vue
+++ b/frontend/src/modules/member/components/list/member-list-toolbar.vue
@@ -237,9 +237,17 @@ const handleMergeMembers = async () => {
 
       fetchMembers({ reload: true });
     })
-    .catch(() => {
+    .catch((error) => {
       Message.closeAll();
-      Message.error('Error merging contacts');
+
+      if (error.response.status === 404) {
+        Message.error('Contacts already merged or deleted', {
+          message: `Sorry, the contacts you are trying to merge might have already been merged or deleted.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error merging contacts');
+      }
     });
 };
 
diff --git a/frontend/src/modules/member/components/member-merge-dialog.vue b/frontend/src/modules/member/components/member-merge-dialog.vue
index cc28ba2ad3..9b1b25e9c2 100644
--- a/frontend/src/modules/member/components/member-merge-dialog.vue
+++ b/frontend/src/modules/member/components/member-merge-dialog.vue
@@ -138,8 +138,15 @@ const mergeSuggestion = () => {
         fetchMembers({ reload: true });
       }
     })
-    .catch(() => {
-      Message.error('There was an error merging contacts');
+    .catch((error) => {
+      if (error.response.status === 404) {
+        Message.error('Contacts already merged or deleted', {
+          message: `Sorry, the contacts you are trying to merge might have already been merged or deleted.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error merging contacts');
+      }
     })
     .finally(() => {
       sendingMerge.value = false;
diff --git a/frontend/src/modules/member/pages/member-merge-suggestions-page.vue b/frontend/src/modules/member/pages/member-merge-suggestions-page.vue
index 71519822ee..38d7c9d130 100644
--- a/frontend/src/modules/member/pages/member-merge-suggestions-page.vue
+++ b/frontend/src/modules/member/pages/member-merge-suggestions-page.vue
@@ -266,8 +266,15 @@ const ignoreSuggestion = () => {
       Message.success('Merging suggestion ignored successfuly');
       fetch();
     })
-    .catch(() => {
-      Message.error('There was an error ignoring the merging suggestion');
+    .catch((error) => {
+      if (error.response.status === 404) {
+        Message.error('Suggestion already merged or ignored', {
+          message: `Sorry, the suggestion you are trying to merge might have already been merged or ignored.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error ignoring the merging suggestion');
+      }
     })
     .finally(() => {
       sendingIgnore.value = false;
@@ -288,8 +295,15 @@ const mergeSuggestion = () => {
       Message.success('Contacts merged successfuly');
       fetch();
     })
-    .catch(() => {
-      Message.error('There was an error merging contacts');
+    .catch((error) => {
+      if (error.response.status === 404) {
+        Message.error('Contacts already merged or deleted', {
+          message: `Sorry, the contacts you are trying to merge might have already been merged or deleted.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error merging contacts');
+      }
     })
     .finally(() => {
       sendingMerge.value = false;
diff --git a/frontend/src/modules/organization/components/list/organization-list-toolbar.vue b/frontend/src/modules/organization/components/list/organization-list-toolbar.vue
index 5196156b8a..e173886e08 100644
--- a/frontend/src/modules/organization/components/list/organization-list-toolbar.vue
+++ b/frontend/src/modules/organization/components/list/organization-list-toolbar.vue
@@ -192,9 +192,17 @@ const handleMergeOrganizations = async () => {
 
       fetchOrganizations({ reload: true });
     })
-    .catch(() => {
+    .catch((error) => {
       Message.closeAll();
-      Message.error('There was an error merging organizations');
+
+      if (error.response.status === 404) {
+        Message.error('Organizations already merged or deleted', {
+          message: `Sorry, the organizations you are trying to merge might have already been merged or deleted.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error merging organizations');
+      }
     });
 };
 
diff --git a/frontend/src/modules/organization/components/organization-merge-dialog.vue b/frontend/src/modules/organization/components/organization-merge-dialog.vue
index 594a6c224a..2736acc574 100644
--- a/frontend/src/modules/organization/components/organization-merge-dialog.vue
+++ b/frontend/src/modules/organization/components/organization-merge-dialog.vue
@@ -155,9 +155,16 @@ const mergeSuggestion = () => {
 
       changeOrganization();
     })
-    .catch(() => {
+    .catch((error) => {
       Message.closeAll();
-      Message.error('There was an error merging organizations');
+      if (error.response.status === 404) {
+        Message.error('Organizations already merged or deleted', {
+          message: `Sorry, the organizations you are trying to merge might have already been merged or deleted.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error merging organizations');
+      }
     })
     .finally(() => {
       sendingMerge.value = false;
diff --git a/frontend/src/modules/organization/pages/organization-merge-suggestions-page.vue b/frontend/src/modules/organization/pages/organization-merge-suggestions-page.vue
index 13af3cf488..0376c3cb0d 100644
--- a/frontend/src/modules/organization/pages/organization-merge-suggestions-page.vue
+++ b/frontend/src/modules/organization/pages/organization-merge-suggestions-page.vue
@@ -276,8 +276,15 @@ const ignoreSuggestion = () => {
       Message.success('Merging suggestion ignored successfuly');
       fetch();
     })
-    .catch(() => {
-      Message.error('There was an error ignoring the merging suggestion');
+    .catch((error) => {
+      if (error.response.status === 404) {
+        Message.error('Suggestion already merged or ignored', {
+          message: `Sorry, the suggestion you are trying to merge might have already been merged or ignored.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error ignoring the merging suggestion');
+      }
     })
     .finally(() => {
       sendingIgnore.value = false;
@@ -313,9 +320,17 @@ const mergeSuggestion = () => {
 
       fetch();
     })
-    .catch((e) => {
+    .catch((error) => {
       Message.closeAll();
-      Message.error('There was an error merging organizations');
+
+      if (error.response.status === 404) {
+        Message.error('Organizations already merged or deleted', {
+          message: `Sorry, the organizations you are trying to merge might have already been merged or deleted.
+          Please refresh to see the updated information.`,
+        });
+      } else {
+        Message.error('There was an error merging organizations');
+      }
     })
     .finally(() => {
       sendingMerge.value = false;