diff --git a/back/Contracts/DTOs/SpendingPlanDto.cs b/back/Contracts/DTOs/SpendingPlanDto.cs
new file mode 100644
index 0000000..fc88578
--- /dev/null
+++ b/back/Contracts/DTOs/SpendingPlanDto.cs
@@ -0,0 +1,10 @@
+namespace Contracts.DTO;
+
+public class SpendingPlanDto
+{
+    public Guid Id { get; set; }
+    public Guid SpendingGroupId { get; set; }
+    public decimal Sum { get; set; }
+    public DateTime StartAt { get; set; }
+    public DateTime EndAt { get; set; }
+}
\ No newline at end of file
diff --git a/back/Contracts/Mappers/SpendingPlanMapper.cs b/back/Contracts/Mappers/SpendingPlanMapper.cs
new file mode 100644
index 0000000..4e4e144
--- /dev/null
+++ b/back/Contracts/Mappers/SpendingPlanMapper.cs
@@ -0,0 +1,16 @@
+using Contracts.DTO;
+using Contracts.ViewModels;
+
+namespace Contracts.Mappers;
+
+public static class SpendingPlanMapper
+{
+    public static SpendingPlanView ToView(this SpendingPlanDto dto) 
+        => new()
+        {
+            Id = dto.Id,
+            StartAt = dto.StartAt,
+            EndAt = dto.EndAt,
+            Sum = dto.Sum
+        };
+}
\ No newline at end of file
diff --git a/back/Contracts/Repositories/ISpendingPlanRepo.cs b/back/Contracts/Repositories/ISpendingPlanRepo.cs
new file mode 100644
index 0000000..229bb7f
--- /dev/null
+++ b/back/Contracts/Repositories/ISpendingPlanRepo.cs
@@ -0,0 +1,13 @@
+using Contracts.DTO;
+using Contracts.SearchModels;
+
+namespace Contracts.Repositories;
+
+public interface ISpendingPlanRepo
+{
+    Task<SpendingPlanDto> Create(SpendingPlanDto dto);
+    Task<SpendingPlanDto?> Update(SpendingPlanDto dto);
+    Task<SpendingPlanDto?> Delete(SpendingPlanSearch search);
+    Task<SpendingPlanDto?> GetDetails(SpendingPlanSearch search);
+    Task<IEnumerable<SpendingPlanDto>> GetList(SpendingGroupSearch? search = null);
+}
\ No newline at end of file
diff --git a/back/Contracts/SearchModels/SpendingPlanSearch.cs b/back/Contracts/SearchModels/SpendingPlanSearch.cs
new file mode 100644
index 0000000..0b53198
--- /dev/null
+++ b/back/Contracts/SearchModels/SpendingPlanSearch.cs
@@ -0,0 +1,6 @@
+namespace Contracts.SearchModels;
+
+public class SpendingPlanSearch
+{
+    public Guid? Id { get; set; }
+}
\ No newline at end of file
diff --git a/back/Contracts/Services/ISpendingPlan.cs b/back/Contracts/Services/ISpendingPlan.cs
new file mode 100644
index 0000000..932c4ca
--- /dev/null
+++ b/back/Contracts/Services/ISpendingPlan.cs
@@ -0,0 +1,14 @@
+using Contracts.DTO;
+using Contracts.SearchModels;
+using Contracts.ViewModels;
+
+namespace Contracts.Services;
+
+public interface ISpendingPlan
+{
+    Task<SpendingPlanView?> GetDetails(SpendingPlanSearch search);
+    Task<IEnumerable<SpendingPlanView>> GetList(SpendingPlanSearch? search = null);
+    Task<SpendingPlanView> Create(SpendingPlanDto spendingPlan);
+    Task<SpendingPlanView?> Delete(SpendingPlanSearch search);
+    Task<SpendingPlanView> Update(SpendingPlanDto spendingPlan);
+}
\ No newline at end of file
diff --git a/back/Contracts/ViewModels/SpendingPlanView.cs b/back/Contracts/ViewModels/SpendingPlanView.cs
new file mode 100644
index 0000000..74ed725
--- /dev/null
+++ b/back/Contracts/ViewModels/SpendingPlanView.cs
@@ -0,0 +1,9 @@
+namespace Contracts.ViewModels;
+
+public class SpendingPlanView
+{
+    public Guid Id { get; set; }
+    public DateTime StartAt { get; set; }
+    public DateTime EndAt { get; set; }
+    public decimal Sum { get; set; }
+}
\ No newline at end of file