diff --git a/packages/survey-core/src/base-interfaces.ts b/packages/survey-core/src/base-interfaces.ts
index 9019cde4fe..c135d71e14 100644
--- a/packages/survey-core/src/base-interfaces.ts
+++ b/packages/survey-core/src/base-interfaces.ts
@@ -136,6 +136,7 @@ export interface ISurvey extends ITextProcessor, ISurveyErrorOwner {
   questionTitlePattern: string;
   getUpdatedQuestionTitle(question: IQuestion, title: string): string;
   getUpdatedQuestionNo(question: IQuestion, no: string): string;
+  getUpdatedPanelNo(question: IPanel, no: string): string;
   getUpdatedPageNo(question: IPage, no: string): string;
   getUpdatedElementTitleActions(
     element: ISurveyElement,
diff --git a/packages/survey-core/src/panel.ts b/packages/survey-core/src/panel.ts
index b49e11b117..7ae4182dfe 100644
--- a/packages/survey-core/src/panel.ts
+++ b/packages/survey-core/src/panel.ts
@@ -2187,13 +2187,14 @@ export class PanelModel extends PanelModelBase implements IElement {
    * @see visibleIf
    */
   public get no(): string {
-    return this.getPropertyValue("no", "");
+    return this.getPropertyValue("no", undefined, () => this.calcNo());
   }
-  protected setNo(visibleIndex: number): void {
-    this.setPropertyValue(
-      "no",
-      Helpers.getNumberByIndex(this.visibleIndex, this.getStartIndex())
-    );
+  private calcNo(): string {
+    let no = Helpers.getNumberByIndex(this.visibleIndex, this.getStartIndex());
+    if(this.survey) {
+      no = this.survey.getUpdatedPanelNo(this, no);
+    }
+    return no || "";
   }
   protected notifyStateChanged(prevState: string): void {
     if(!this.isLoadingFromJson) {
@@ -2218,7 +2219,7 @@ export class PanelModel extends PanelModelBase implements IElement {
       visibleIndex = index;
     }
     this.setPropertyValue("visibleIndex", visibleIndex);
-    this.setNo(visibleIndex);
+    this.resetPropertyValue("no");
     return visibleIndex < 0 ? 0 : 1;
   }
   protected getPanelStartIndex(index: number): number {
diff --git a/packages/survey-core/src/survey-events-api.ts b/packages/survey-core/src/survey-events-api.ts
index a1e15f107f..7aa2c2730a 100644
--- a/packages/survey-core/src/survey-events-api.ts
+++ b/packages/survey-core/src/survey-events-api.ts
@@ -414,6 +414,12 @@ export interface GetPageNumberEvent extends PageEventMixin {
    */
   number: string;
 }
+export interface GetPanelNumberEvent extends PanelEventMixin {
+  /**
+   * A panel number. Note that this is a string value that contains not only the number itself but also the characters that separate the number from the panel title: `"1. "`, `"2. "`, etc. You can change this parameter's value.
+   */
+  number: string;
+}
 export interface GetProgressTextEvent {
   /**
    * The number of questions with input fields. [Image](https://surveyjs.io/form-library/examples/add-image-and-video-to-survey/), [HTML](https://surveyjs.io/form-library/examples/questiontype-html/), and [Expression](https://surveyjs.io/form-library/examples/questiontype-expression/) questions are not counted.
diff --git a/packages/survey-core/src/survey.ts b/packages/survey-core/src/survey.ts
index 4ea2f69b33..d284dc6e1c 100644
--- a/packages/survey-core/src/survey.ts
+++ b/packages/survey-core/src/survey.ts
@@ -58,7 +58,7 @@ import {
   TriggerExecutedEvent, CompletingEvent, CompleteEvent, ShowingPreviewEvent, NavigateToUrlEvent, CurrentPageChangingEvent, CurrentPageChangedEvent,
   ValueChangingEvent, ValueChangedEvent, VariableChangedEvent, QuestionVisibleChangedEvent, PageVisibleChangedEvent, PanelVisibleChangedEvent, QuestionCreatedEvent,
   QuestionAddedEvent, QuestionRemovedEvent, PanelAddedEvent, PanelRemovedEvent, PageAddedEvent, ValidateQuestionEvent, SettingQuestionErrorsEvent, ValidatePanelEvent,
-  ErrorCustomTextEvent, ValidatedErrorsOnCurrentPageEvent, ProcessHtmlEvent, GetQuestionTitleEvent, GetTitleTagNameEvent, GetQuestionNumberEvent, GetPageNumberEvent, GetProgressTextEvent,
+  ErrorCustomTextEvent, ValidatedErrorsOnCurrentPageEvent, ProcessHtmlEvent, GetQuestionTitleEvent, GetTitleTagNameEvent, GetQuestionNumberEvent, GetPageNumberEvent, GetPanelNumberEvent, GetProgressTextEvent,
   TextMarkdownEvent, TextRenderAsEvent, SendResultEvent, GetResultEvent, UploadFilesEvent, DownloadFileEvent, ClearFilesEvent, LoadChoicesFromServerEvent,
   ProcessTextValueEvent, UpdateQuestionCssClassesEvent, UpdatePanelCssClassesEvent, UpdatePageCssClassesEvent, UpdateChoiceItemCssEvent, AfterRenderSurveyEvent,
   AfterRenderPageEvent, AfterRenderQuestionEvent, AfterRenderQuestionInputEvent, AfterRenderPanelEvent, FocusInQuestionEvent, FocusInPanelEvent,
@@ -429,6 +429,12 @@ export class SurveyModel extends SurveyElementCore
    * @deprecated
    */
   public onGetQuestionNo: EventBase<SurveyModel, GetQuestionNumberEvent> = this.onGetQuestionNumber;
+  /**
+   * An event that is raised before the survey calculates a panel number. Handle this event to modify panel numbers.
+   *
+   * This event is raised only for the panels with a [specified title](https://surveyjs.io/form-library/documentation/api-reference/panel-model#title) and [visible number](https://surveyjs.io/form-library/documentation/api-reference/panel-model#showNumber).
+   */
+  public onGetPanelNumber: EventBase<SurveyModel, GetPanelNumberEvent> = this.addEvent<SurveyModel, GetPanelNumberEvent>();
   /**
    * An event that is raised before the survey calculates a page number. Handle this event to modify page numbers.
    *
@@ -987,6 +993,9 @@ export class SurveyModel extends SurveyElementCore
     this.onGetQuestionNumber.onCallbacksChanged = () => {
       this.resetVisibleIndexes();
     };
+    this.onGetPanelNumber.onCallbacksChanged = () => {
+      this.resetVisibleIndexes();
+    };
     this.onGetProgressText.onCallbacksChanged = () => {
       this.updateProgressText();
     };
@@ -2719,6 +2728,12 @@ export class SurveyModel extends SurveyElementCore
     this.onGetQuestionNumber.fire(this, options);
     return options.no === no ? options.number : options.no;
   }
+  getUpdatedPanelNo(panel: PanelModel, no: string): string {
+    if (this.onGetPanelNumber.isEmpty) return no;
+    const options: GetPanelNumberEvent = { panel: panel, number: no };
+    this.onGetPanelNumber.fire(this, options);
+    return options.number;
+  }
   getUpdatedPageNo(page: PageModel, no: string): string {
     if (this.onGetPageNumber.isEmpty) return no;
     const options: GetPageNumberEvent = { page: page, number: no };
diff --git a/packages/survey-core/tests/paneltests.ts b/packages/survey-core/tests/paneltests.ts
index eb075b72ef..d20570d85d 100644
--- a/packages/survey-core/tests/paneltests.ts
+++ b/packages/survey-core/tests/paneltests.ts
@@ -3397,4 +3397,56 @@ QUnit.test("Nested pages", function (assert) {
   assert.equal(page1.getTemplate(), "page", "template #3");
   assert.equal(page1.survey.state, "running", "survey state #3");
   assert.equal(page1.isDisposed, false, "The page is not disposed");
-});
\ No newline at end of file
+});
+QUnit.test("survey.onGetPanelNumber", function (assert) {
+  const survey = new SurveyModel({
+    elements: [
+      {
+        type: "panel", name: "panel1", title: "Panel 1",
+        showNumber: true, showQuestionNumbers: "onpanel",
+        elements: [
+          { type: "panel", name: "panel2",
+            showNumber: true, showQuestionNumbers: "onpanel", title: "Panel 2",
+            elements: [
+              { type: "text", name: "q1" },
+              { type: "text", name: "q2" }
+            ]
+          },
+          { type: "text", name: "q3" },
+          { type: "text", name: "q4" }
+        ]
+      },
+      {
+        type: "panel", name: "panel3",
+        showNumber: true, showQuestionNumbers: "onpanel", title: "Panel 3",
+        elements: [
+          { type: "text", name: "q5" },
+          { type: "text", name: "q6" }
+        ]
+      },
+      { type: "text", name: "q7" }
+    ]
+  });
+  survey.onGetQuestionNumber.add((sender, options) => {
+    const parent: any = options.question.parent;
+    if(!!parent && parent.no) {
+      options.number = parent.no + options.number;
+    }
+  });
+  survey.onGetPanelNumber.add((sender, options) => {
+    const parent: any = options.panel.parent;
+    if(!!parent && parent.no) {
+      options.number = parent.no + options.number;
+    }
+  });
+  assert.equal(survey.getPanelByName("panel1").no, "1.", "panel1.no");
+  assert.equal(survey.getPanelByName("panel2").no, "1.1.", "panel2.no");
+  assert.equal(survey.getPanelByName("panel3").no, "2.", "panel3.no");
+  assert.equal(survey.getQuestionByName("q1").no, "1.1.1.", "q1.no");
+  assert.equal(survey.getQuestionByName("q2").no, "1.1.2.", "q2.no");
+  assert.equal(survey.getQuestionByName("q3").no, "1.2.", "q3.no");
+  assert.equal(survey.getQuestionByName("q4").no, "1.3.", "q4.no");
+  assert.equal(survey.getQuestionByName("q5").no, "2.1.", "q5.no");
+  assert.equal(survey.getQuestionByName("q6").no, "2.2.", "q6.no");
+  assert.equal(survey.getQuestionByName("q7").no, "3.", "q7.no");
+});