diff --git a/app/controllers/api/v1/accounts/conversations_controller.rb b/app/controllers/api/v1/accounts/conversations_controller.rb
index 1b3933d99..b464f90d3 100644
--- a/app/controllers/api/v1/accounts/conversations_controller.rb
+++ b/app/controllers/api/v1/accounts/conversations_controller.rb
@@ -2,6 +2,7 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
   include Events::Types
   include DateRangeHelper
   include HmacConcern
+  include ConversationCustomAttributesConcern
 
   before_action :conversation, except: [:index, :meta, :search, :create, :filter]
   before_action :inbox, :contact, :contact_inbox, only: [:create]
@@ -129,11 +130,6 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
     update_last_seen_on_conversation(last_seen_at, true)
   end
 
-  def custom_attributes
-    @conversation.custom_attributes = params.permit(custom_attributes: {})[:custom_attributes]
-    @conversation.save!
-  end
-
   def destroy
     authorize @conversation, :destroy?
     ::Conversations::DeleteService.new(conversation: @conversation, user: Current.user, ip: request.ip).perform
diff --git a/app/controllers/concerns/conversation_custom_attributes_concern.rb b/app/controllers/concerns/conversation_custom_attributes_concern.rb
new file mode 100644
index 000000000..835395e0c
--- /dev/null
+++ b/app/controllers/concerns/conversation_custom_attributes_concern.rb
@@ -0,0 +1,15 @@
+module ConversationCustomAttributesConcern
+  def custom_attributes
+    attributes = params.permit(custom_attributes: {})[:custom_attributes]
+    # When `merge` is truthy, only the keys sent are updated and the rest are kept, matching the contacts endpoint.
+    # Replace stays the default so existing integrations are unaffected.
+    attributes = @conversation.custom_attributes.merge(attributes || {}) if ActiveModel::Type::Boolean.new.cast(params[:merge])
+    @conversation.custom_attributes = attributes
+    @conversation.save!
+  end
+
+  def destroy_custom_attributes
+    @conversation.custom_attributes = @conversation.custom_attributes.excluding(params[:custom_attributes])
+    @conversation.save!
+  end
+end
diff --git a/app/views/api/v1/accounts/conversations/destroy_custom_attributes.json.jbuilder b/app/views/api/v1/accounts/conversations/destroy_custom_attributes.json.jbuilder
new file mode 100644
index 000000000..1ca512802
--- /dev/null
+++ b/app/views/api/v1/accounts/conversations/destroy_custom_attributes.json.jbuilder
@@ -0,0 +1 @@
+json.custom_attributes @conversation.custom_attributes
diff --git a/config/routes.rb b/config/routes.rb
index 3655561af..538330b70 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -173,6 +173,7 @@ Rails.application.routes.draw do
               post :update_last_seen
               post :unread
               post :custom_attributes
+              post :destroy_custom_attributes
               get :attachments
               get :inbox_assistant
               get :reporting_events if ChatwootApp.enterprise?
diff --git a/spec/controllers/api/v1/accounts/conversations_controller_spec.rb b/spec/controllers/api/v1/accounts/conversations_controller_spec.rb
index ea56f906a..7987d8e51 100644
--- a/spec/controllers/api/v1/accounts/conversations_controller_spec.rb
+++ b/spec/controllers/api/v1/accounts/conversations_controller_spec.rb
@@ -1212,6 +1212,30 @@ RSpec.describe 'Conversations API', type: :request do
         expect(conversation.reload.custom_attributes).not_to be_nil
         expect(conversation.reload.custom_attributes.count).to eq 3
       end
+
+      it 'merges custom attributes when merge is enabled' do
+        conversation.update!(custom_attributes: { existing_key: 'keep', user_id: 1 })
+
+        post "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}/custom_attributes",
+             headers: agent.create_new_auth_token,
+             params: { custom_attributes: { user_id: 1001 }, merge: true },
+             as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(conversation.reload.custom_attributes).to eq({ 'existing_key' => 'keep', 'user_id' => 1001 })
+      end
+
+      it 'replaces custom attributes by default' do
+        conversation.update!(custom_attributes: { existing_key: 'gone' })
+
+        post "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}/custom_attributes",
+             headers: agent.create_new_auth_token,
+             params: { custom_attributes: { user_id: 1001 } },
+             as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(conversation.reload.custom_attributes).to eq({ 'user_id' => 1001 })
+      end
     end
 
     context 'when it is a bot' do
@@ -1236,6 +1260,37 @@ RSpec.describe 'Conversations API', type: :request do
     end
   end
 
+  describe 'POST /api/v1/accounts/{account.id}/conversations/:id/destroy_custom_attributes' do
+    let(:conversation) { create(:conversation, account: account, custom_attributes: { test: 'test', test1: 'test1' }) }
+
+    context 'when it is an unauthenticated user' do
+      it 'returns unauthorized' do
+        post "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}/destroy_custom_attributes"
+
+        expect(response).to have_http_status(:unauthorized)
+      end
+    end
+
+    context 'when it is an authenticated user' do
+      let(:agent) { create(:user, account: account, role: :agent) }
+
+      before do
+        create(:inbox_member, user: agent, inbox: conversation.inbox)
+      end
+
+      it 'deletes the given custom attribute' do
+        post "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}/destroy_custom_attributes",
+             headers: agent.create_new_auth_token,
+             params: { custom_attributes: ['test'] },
+             as: :json
+
+        expect(response).to have_http_status(:ok)
+        expect(conversation.reload.custom_attributes).to eq({ 'test1' => 'test1' })
+        expect(response.parsed_body['custom_attributes']).to eq({ 'test1' => 'test1' })
+      end
+    end
+  end
+
   describe 'GET /api/v1/accounts/{account.id}/conversations/:id/attachments' do
     let(:conversation) { create(:conversation, account: account) }
 
diff --git a/swagger/paths/application/conversation/custom_attributes.yml b/swagger/paths/application/conversation/custom_attributes.yml
index 6e5786742..97ff0f7c7 100644
--- a/swagger/paths/application/conversation/custom_attributes.yml
+++ b/swagger/paths/application/conversation/custom_attributes.yml
@@ -20,6 +20,13 @@ requestBody:
             example:
               order_id: '12345'
               previous_conversation: '67890'
+          merge:
+            type: boolean
+            default: false
+            description: >-
+              When true, only the keys sent in `custom_attributes` are updated and the remaining
+              keys are kept intact. When false (default), the whole custom attributes hash is
+              replaced. Use the destroy_custom_attributes endpoint to remove keys.
 responses:
   '200':
     description: Success
diff --git a/swagger/paths/application/conversation/destroy_custom_attributes.yml b/swagger/paths/application/conversation/destroy_custom_attributes.yml
new file mode 100644
index 000000000..0b1fada40
--- /dev/null
+++ b/swagger/paths/application/conversation/destroy_custom_attributes.yml
@@ -0,0 +1,47 @@
+tags:
+  - Conversations
+operationId: destroy-custom-attributes-of-a-conversation
+summary: Destroy Custom Attributes
+description: Removes the given custom attribute keys from a conversation
+security:
+  - userApiKey: []
+requestBody:
+  required: true
+  content:
+    application/json:
+      schema:
+        type: object
+        required:
+          - custom_attributes
+        properties:
+          custom_attributes:
+            type: array
+            items:
+              type: string
+            description: The list of custom attribute keys to remove from the conversation
+            example:
+              - order_id
+              - previous_conversation
+responses:
+  '200':
+    description: Success
+    content:
+      application/json:
+        schema:
+          type: object
+          properties:
+            custom_attributes:
+              type: object
+              description: The remaining custom attributes of the conversation
+  '401':
+    description: Unauthorized
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'
+  '404':
+    description: Conversation not found
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'
diff --git a/swagger/paths/index.yml b/swagger/paths/index.yml
index e610c9662..7f80c3061 100644
--- a/swagger/paths/index.yml
+++ b/swagger/paths/index.yml
@@ -381,6 +381,13 @@
   post:
     $ref: ./application/conversation/custom_attributes.yml
 
+/api/v1/accounts/{account_id}/conversations/{conversation_id}/destroy_custom_attributes:
+  parameters:
+    - $ref: '#/components/parameters/account_id'
+    - $ref: '#/components/parameters/conversation_id'
+  post:
+    $ref: ./application/conversation/destroy_custom_attributes.yml
+
 # Conversations Assignments
 
 /api/v1/accounts/{account_id}/conversations/{conversation_id}/assignments:
diff --git a/swagger/swagger.json b/swagger/swagger.json
index 61aaf55a8..0de86b309 100644
--- a/swagger/swagger.json
+++ b/swagger/swagger.json
@@ -5063,6 +5063,11 @@
                       "order_id": "12345",
                       "previous_conversation": "67890"
                     }
+                  },
+                  "merge": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "When true, only the keys sent in `custom_attributes` are updated and the remaining keys are kept intact. When false (default), the whole custom attributes hash is replaced. Use the destroy_custom_attributes endpoint to remove keys."
                   }
                 }
               }
@@ -5109,6 +5114,93 @@
         }
       }
     },
+    "/api/v1/accounts/{account_id}/conversations/{conversation_id}/destroy_custom_attributes": {
+      "parameters": [
+        {
+          "$ref": "#/components/parameters/account_id"
+        },
+        {
+          "$ref": "#/components/parameters/conversation_id"
+        }
+      ],
+      "post": {
+        "tags": [
+          "Conversations"
+        ],
+        "operationId": "destroy-custom-attributes-of-a-conversation",
+        "summary": "Destroy Custom Attributes",
+        "description": "Removes the given custom attribute keys from a conversation",
+        "security": [
+          {
+            "userApiKey": []
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "required": [
+                  "custom_attributes"
+                ],
+                "properties": {
+                  "custom_attributes": {
+                    "type": "array",
+                    "items": {
+                      "type": "string"
+                    },
+                    "description": "The list of custom attribute keys to remove from the conversation",
+                    "example": [
+                      "order_id",
+                      "previous_conversation"
+                    ]
+                  }
+                }
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "properties": {
+                    "custom_attributes": {
+                      "type": "object",
+                      "description": "The remaining custom attributes of the conversation"
+                    }
+                  }
+                }
+              }
+            }
+          },
+          "401": {
+            "description": "Unauthorized",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/bad_request_error"
+                }
+              }
+            }
+          },
+          "404": {
+            "description": "Conversation not found",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/bad_request_error"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/api/v1/accounts/{account_id}/conversations/{conversation_id}/assignments": {
       "parameters": [
         {
diff --git a/swagger/tag_groups/application_swagger.json b/swagger/tag_groups/application_swagger.json
index 1c72fe3e1..3173c28ac 100644
--- a/swagger/tag_groups/application_swagger.json
+++ b/swagger/tag_groups/application_swagger.json
@@ -3606,6 +3606,11 @@
                       "order_id": "12345",
                       "previous_conversation": "67890"
                     }
+                  },
+                  "merge": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "When true, only the keys sent in `custom_attributes` are updated and the remaining keys are kept intact. When false (default), the whole custom attributes hash is replaced. Use the destroy_custom_attributes endpoint to remove keys."
                   }
                 }
               }
@@ -3652,6 +3657,93 @@
         }
       }
     },
+    "/api/v1/accounts/{account_id}/conversations/{conversation_id}/destroy_custom_attributes": {
+      "parameters": [
+        {
+          "$ref": "#/components/parameters/account_id"
+        },
+        {
+          "$ref": "#/components/parameters/conversation_id"
+        }
+      ],
+      "post": {
+        "tags": [
+          "Conversations"
+        ],
+        "operationId": "destroy-custom-attributes-of-a-conversation",
+        "summary": "Destroy Custom Attributes",
+        "description": "Removes the given custom attribute keys from a conversation",
+        "security": [
+          {
+            "userApiKey": []
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "required": [
+                  "custom_attributes"
+                ],
+                "properties": {
+                  "custom_attributes": {
+                    "type": "array",
+                    "items": {
+                      "type": "string"
+                    },
+                    "description": "The list of custom attribute keys to remove from the conversation",
+                    "example": [
+                      "order_id",
+                      "previous_conversation"
+                    ]
+                  }
+                }
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Success",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "properties": {
+                    "custom_attributes": {
+                      "type": "object",
+                      "description": "The remaining custom attributes of the conversation"
+                    }
+                  }
+                }
+              }
+            }
+          },
+          "401": {
+            "description": "Unauthorized",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/bad_request_error"
+                }
+              }
+            }
+          },
+          "404": {
+            "description": "Conversation not found",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/bad_request_error"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/api/v1/accounts/{account_id}/conversations/{conversation_id}/assignments": {
       "parameters": [
         {