diff --git a/packages/flutter_availability_data_interface/lib/src/models/availability.dart b/packages/flutter_availability_data_interface/lib/src/models/availability.dart
index ce92ff5..e189bfc 100644
--- a/packages/flutter_availability_data_interface/lib/src/models/availability.dart
+++ b/packages/flutter_availability_data_interface/lib/src/models/availability.dart
@@ -8,6 +8,7 @@ class AvailabilityModel {
     required this.endDate,
     required this.breaks,
     this.id,
+    this.templateId,
   });
 
   /// the identifier for this availability
@@ -16,6 +17,10 @@ class AvailabilityModel {
   /// The uniquely identifiable string for who or what the
   final String userId;
 
+  /// The identifier of the [AvailabilityTemplateModel] that this availability
+  /// is associated with if any.
+  final String? templateId;
+
   /// The from date of this availability.
   ///
   /// [startDate] will always have to be before the end date.
@@ -34,6 +39,7 @@ class AvailabilityModel {
   AvailabilityModel copyWith({
     String? id,
     String? userId,
+    String? templateId,
     DateTime? startDate,
     DateTime? endDate,
     List<AvailabilityBreakModel>? breaks,
@@ -41,6 +47,7 @@ class AvailabilityModel {
       AvailabilityModel(
         id: id ?? this.id,
         userId: userId ?? this.userId,
+        templateId: templateId ?? this.templateId,
         startDate: startDate ?? this.startDate,
         endDate: endDate ?? this.endDate,
         breaks: breaks ?? this.breaks,
diff --git a/packages/flutter_availability_data_interface/lib/src/models/templates.dart b/packages/flutter_availability_data_interface/lib/src/models/templates.dart
index a11efdf..55fc5f9 100644
--- a/packages/flutter_availability_data_interface/lib/src/models/templates.dart
+++ b/packages/flutter_availability_data_interface/lib/src/models/templates.dart
@@ -70,7 +70,12 @@ class AvailabilityTemplateModel {
 
   /// applies the template to a range of dates
   List<AvailabilityModel> apply(DateTime start, DateTime end) =>
-      templateData.apply(userId: userId, start: start, end: end);
+      templateData.apply(
+        userId: userId,
+        start: start,
+        end: end,
+        templateId: id,
+      );
 }
 
 /// Used as the key for defining week-based templates
@@ -124,6 +129,7 @@ abstract interface class TemplateData {
     required String userId,
     required DateTime start,
     required DateTime end,
+    required String? templateId,
   });
 
   /// Serialize the template to representational data
@@ -199,9 +205,9 @@ class WeekTemplateData implements TemplateData {
     required String userId,
     required DateTime start,
     required DateTime end,
+    String? templateId,
   }) {
     var dates = _getDatesBetween(start, end);
-
     return [
       for (var date in dates)
         if (data.containsKey(WeekDay.fromDateTime(date)))
@@ -209,6 +215,7 @@ class WeekTemplateData implements TemplateData {
             start: date,
             end: date,
             userId: userId,
+            templateId: templateId,
           ),
     ];
   }
@@ -266,6 +273,7 @@ class DayTemplateData implements TemplateData {
     required String userId,
     required DateTime start,
     required DateTime end,
+    String? templateId,
   }) {
     var dates = _getDatesBetween(start, end);
 
@@ -273,6 +281,7 @@ class DayTemplateData implements TemplateData {
       for (var date in dates) ...[
         AvailabilityModel(
           userId: userId,
+          templateId: templateId,
           startDate: date.mergeTime(startTime),
           endDate: date.mergeTime(endTime),
           breaks: [
diff --git a/packages/flutter_availability_data_interface/test/models_templates_test.dart b/packages/flutter_availability_data_interface/test/models_templates_test.dart
index 5e3b44c..de4369f 100644
--- a/packages/flutter_availability_data_interface/test/models_templates_test.dart
+++ b/packages/flutter_availability_data_interface/test/models_templates_test.dart
@@ -30,6 +30,7 @@ void main() {
         var sunday = createTemplate(7);
 
         var sut = AvailabilityTemplateModel(
+          id: "",
           userId: "",
           name: "",
           color: 0,
@@ -142,6 +143,7 @@ void main() {
         }
 
         var weektemplate = AvailabilityTemplateModel(
+          id: "id",
           userId: "1",
           name: "test",
           color: 0xFFAABBCC,