diff --git a/AB-API/AB.WEB.csproj b/AB-API/AB.WEB.csproj
index 13d8260..387fc6d 100644
--- a/AB-API/AB.WEB.csproj
+++ b/AB-API/AB.WEB.csproj
@@ -12,7 +12,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.2.3" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/AB-API/Program.cs b/AB-API/Program.cs
index 26edc72..aea83c9 100644
--- a/AB-API/Program.cs
+++ b/AB-API/Program.cs
@@ -5,12 +5,15 @@ using AB.Services;
 using AB.Services.Abstractions;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.OpenApi.Models;
+using System.Text.Json.Serialization;
 
 var builder = WebApplication.CreateBuilder(args);
 
 // Add services to the container.
 
-builder.Services.AddControllers().AddApplicationPart(typeof(AB.API.AssemblyReference).Assembly);
+builder.Services.AddControllers().AddApplicationPart(typeof(AB.API.AssemblyReference).Assembly)
+    .AddJsonOptions(options => options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter()));
+
 // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen(c => c.SwaggerDoc("v1", new OpenApiInfo { Title = "AB-API", Version = "v1", Description = "An Api for the AB-Application" }));
diff --git a/AB.API/Controllers/BusinessPartner/SupplierController.cs b/AB.API/Controllers/BusinessPartner/SupplierController.cs
index b0abe21..0977013 100644
--- a/AB.API/Controllers/BusinessPartner/SupplierController.cs
+++ b/AB.API/Controllers/BusinessPartner/SupplierController.cs
@@ -28,9 +28,9 @@ public class SupplierController : ControllerBase
     }
 
     [HttpPost]
-    public async Task<CreatedAtActionResult> CreateSupplier([FromBody] SupplierForCreationDto supplierForCreation)
+    public async Task<CreatedAtActionResult> CreateSupplier([FromBody] SupplierForCreationDto supplierForCreation, CancellationToken cancellationToken)
     {
-        var supplierDto = await _supplierService.CreateAsync(supplierForCreation);
+        var supplierDto = await _supplierService.CreateAsync(supplierForCreation, cancellationToken);
 
         return CreatedAtAction(nameof(CreateSupplier), new { id = supplierDto.Id }, supplierDto);
     }
diff --git a/AB.Contracts/ContactPersonDto.cs b/AB.Contracts/ContactPersonDto.cs
new file mode 100644
index 0000000..43ebc61
--- /dev/null
+++ b/AB.Contracts/ContactPersonDto.cs
@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AB.Contracts;
+
+public class ContactPersonDto
+{
+
+
+
+    public string Name { get; set; }
+
+    public string Salutation { get; set; }
+
+    public string PhoneNumer { get; set; }
+
+    public string Email { get; set; }
+
+}
+
diff --git a/AB.Contracts/CustomerDto.cs b/AB.Contracts/CustomerDto.cs
index b73c023..0846bf6 100644
--- a/AB.Contracts/CustomerDto.cs
+++ b/AB.Contracts/CustomerDto.cs
@@ -16,5 +16,4 @@ public class CustomerDto
     public string Iban { get; set; }
 
     public string PhoneNumber { get; set; }
-
 }
diff --git a/AB.Contracts/PreferredCommunicationType.cs b/AB.Contracts/PreferredCommunicationType.cs
new file mode 100644
index 0000000..bfbe611
--- /dev/null
+++ b/AB.Contracts/PreferredCommunicationType.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AB.Contracts
+{
+    public enum PreferredCommunicationType
+    {
+        [EnumMember(Value = "Email")]
+        Email,
+
+        [EnumMember(Value = "Postal")]
+        Postal,
+        
+        [EnumMember(Value = "Phone")]
+        Phone,
+
+        [EnumMember(Value = "Phone")]
+        Fax
+    }
+}
diff --git a/AB.Contracts/SupplierForCreationDto.cs b/AB.Contracts/SupplierForCreationDto.cs
index 04c7b74..fd7a7aa 100644
--- a/AB.Contracts/SupplierForCreationDto.cs
+++ b/AB.Contracts/SupplierForCreationDto.cs
@@ -1,11 +1,27 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.Runtime.Serialization;
 
 namespace AB.Contracts;
 
 public class SupplierForCreationDto
 {
+
+    public string Salutation { get; set; }
+
+    public string Name1 { get; set; }
+
+    public string Name2 { get; set; }
+
+    public string Email { get; set; }
+
+    public string PhoneNumber { get; set; }
+
+    public string TaxId { get; set; }
+
+    [DataMember(Name = "PreferredCommunication", EmitDefaultValue = true)]
+    public PreferredCommunicationType PreferredCommunication { get; set; }
+
+    public IEnumerable<ContactPersonDto> ContactPersons { get; set; }
+
+
+
 }
diff --git a/AB.Domain/Repositories/ICustomerRepository.cs b/AB.Domain/Repositories/ICustomerRepository.cs
index 5365510..62f9d6d 100644
--- a/AB.Domain/Repositories/ICustomerRepository.cs
+++ b/AB.Domain/Repositories/ICustomerRepository.cs
@@ -10,7 +10,7 @@ namespace AB.Domain.Repositories;
 public interface ICustomerRepository
 {
     public Task<IEnumerable<Customer>> GetAllAsync(CancellationToken cancellationToken);
-    Task<Customer> GetByIdAsync(Guid customerId, CancellationToken cancellationToken);
-    void Insert(Customer customer);
-    void Remove(Customer customer);
+    public Task<Customer> GetByIdAsync(Guid customerId, CancellationToken cancellationToken);
+    public void Insert(Customer customer);
+    public void Remove(Customer customer);
 }
diff --git a/AB.Domain/Repositories/ISupplierRepository.cs b/AB.Domain/Repositories/ISupplierRepository.cs
index 7cd292a..7d3d5d2 100644
--- a/AB.Domain/Repositories/ISupplierRepository.cs
+++ b/AB.Domain/Repositories/ISupplierRepository.cs
@@ -1,11 +1,11 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using AB.Domain.Entities;
 
 namespace AB.Domain.Repositories;
 
-public class ISupplierRepository
+public interface ISupplierRepository
 {
+    public Task<IEnumerable<Supplier>> GetAllAsync(CancellationToken cancellationToken);
+    public Task<Supplier> GetByIdAsync(Guid supplierId, CancellationToken cancellationToken);
+    public void Insert(Supplier supplier);
+    public void Remove(Supplier supplier);
 }
diff --git a/AB.Persistence/RepoDbContext.cs b/AB.Persistence/RepoDbContext.cs
index 28a886c..ab8df82 100644
--- a/AB.Persistence/RepoDbContext.cs
+++ b/AB.Persistence/RepoDbContext.cs
@@ -1,10 +1,5 @@
 using AB.Domain.Entities;
 using Microsoft.EntityFrameworkCore;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace AB.Persistence;
 
@@ -12,7 +7,7 @@ public sealed class RepoDbContext : DbContext
 {
 
     public RepoDbContext(DbContextOptions options)
-        : base (options)
+        : base(options)
     {
     }
 
diff --git a/AB.Persistence/Repos/SupplierRepository.cs b/AB.Persistence/Repos/SupplierRepository.cs
index 04d4a11..41c14c1 100644
--- a/AB.Persistence/Repos/SupplierRepository.cs
+++ b/AB.Persistence/Repos/SupplierRepository.cs
@@ -1,4 +1,7 @@
-using System;
+using AB.Domain.Entities;
+using AB.Domain.Repositories;
+using Microsoft.EntityFrameworkCore;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -6,9 +9,33 @@ using System.Threading.Tasks;
 
 namespace AB.Persistence.Repos;
 
-public class SupplierRepository
+public class SupplierRepository : ISupplierRepository
 {
+    private readonly RepoDbContext _dbContext;
 
+    public SupplierRepository(RepoDbContext dbContext)
+    {
+        _dbContext = dbContext;
+    }
 
+    public async Task<IEnumerable<Supplier>> GetAllAsync(CancellationToken cancellationToken)
+    {
+        return await _dbContext.Suppliers.ToListAsync(cancellationToken);
+    }
 
+    public async Task<Supplier> GetByIdAsync(Guid supplierId, CancellationToken cancellationToken)
+    {
+        return await _dbContext.Suppliers.FirstOrDefaultAsync(x => x.SupplierId == supplierId, cancellationToken);
+    }
+
+    public void Insert(Supplier supplier)
+    {
+        _dbContext.Add(supplier);
+    }
+
+    public void Remove(Supplier supplier)
+    {
+        
+        _dbContext.Suppliers.Remove(supplier);
+    }
 }
diff --git a/AB.Services.Abstractions/ISupplierService.cs b/AB.Services.Abstractions/ISupplierService.cs
index e00decf..ba106d9 100644
--- a/AB.Services.Abstractions/ISupplierService.cs
+++ b/AB.Services.Abstractions/ISupplierService.cs
@@ -4,8 +4,8 @@ namespace AB.Services.Abstractions;
 
 public interface ISupplierService
 {
-    Task<SupplierDto> CreateAsync(SupplierForCreationDto supplierForCreation);
-    Task DeleteAsync(Guid supplierId, CancellationToken cancellationToken);
-    Task<IEnumerable<SupplierDto>> GetAllAsync(CancellationToken cancellationToken);
-    Task<SupplierDto> GetSupplierByIdAsync(Guid supplierId, CancellationToken cancellationToken);
+    public Task<SupplierDto> CreateAsync(SupplierForCreationDto supplierForCreation, CancellationToken cancellationToken);
+    public Task DeleteAsync(Guid supplierId, CancellationToken cancellationToken);
+    public Task<IEnumerable<SupplierDto>> GetAllAsync(CancellationToken cancellationToken);
+    public Task<SupplierDto> GetSupplierByIdAsync(Guid supplierId, CancellationToken cancellationToken);
 }
diff --git a/AB.Services/CustomerService.cs b/AB.Services/CustomerService.cs
index 8bb7e68..7bc45c0 100644
--- a/AB.Services/CustomerService.cs
+++ b/AB.Services/CustomerService.cs
@@ -21,8 +21,6 @@ public class CustomerService : ICustomerService
 
     public async Task<CustomerDto> CreateAsync(CustomerForCreationDto customerForCreation, CancellationToken cancellationToken = default)
     {
-
-
         var customer = new Customer
         {
             Salutation = customerForCreation.Salutaion,
@@ -46,7 +44,7 @@ public class CustomerService : ICustomerService
     {
         var customer = await _customerRepository.GetByIdAsync(customerId, cancellationToken);
 
-        if (customer == null)
+        if (customer is null)
         {
             throw new BusinessPartnerNotFoundException(customerId);
         }
@@ -122,7 +120,7 @@ public class CustomerService : ICustomerService
 
     public static void SetIfContains<T>(T value, Customer customer, string propertyName)
     {
-        if (value is not null)
+        if (value is not null && !string.IsNullOrWhiteSpace(propertyName))
         {
             customer.GetType().GetProperty(propertyName).SetValue(customer, value);
 
diff --git a/AB.Services/SupplierService.cs b/AB.Services/SupplierService.cs
new file mode 100644
index 0000000..faaf70b
--- /dev/null
+++ b/AB.Services/SupplierService.cs
@@ -0,0 +1,87 @@
+using AB.Contracts;
+using AB.Domain.Entities;
+using AB.Domain.Exceptions;
+using AB.Domain.Repositories;
+using AB.Services.Abstractions;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AB.Services
+{
+    public class SupplierService : ISupplierService
+    {
+
+        private readonly ISupplierRepository _supplierRepository;
+
+        private readonly IUnitOfWork _unitOfWork;
+
+        public SupplierService(ISupplierRepository supplierRepository, IUnitOfWork unitOfWork)
+        {
+            _supplierRepository = supplierRepository;
+            _unitOfWork = unitOfWork;
+        }
+
+        public async Task<SupplierDto> CreateAsync(SupplierForCreationDto supplierForCreation, CancellationToken cancellationToken)
+        {
+            var supplier = new Supplier
+            {
+
+            };
+
+            _supplierRepository.Insert(supplier);
+
+            await _unitOfWork.SaveChangesAsync(cancellationToken);
+
+            var supplierDto = ConvertToSupplierDto(supplier);
+
+            return supplierDto;
+        }
+
+        public async Task DeleteAsync(Guid supplierId, CancellationToken cancellationToken)
+        {
+            var supplier = await _supplierRepository.GetByIdAsync(supplierId, cancellationToken);
+
+            if (supplier is null)
+            {
+                throw new BusinessPartnerNotFoundException(supplierId);
+            }
+
+            _supplierRepository.Remove(supplier);
+
+            await _unitOfWork.SaveChangesAsync(cancellationToken);
+        }
+
+        public async Task<IEnumerable<SupplierDto>> GetAllAsync(CancellationToken cancellationToken)
+        {
+            var supplierList = await _supplierRepository.GetAllAsync(cancellationToken);
+
+            var supplierDtoList = supplierList.Select(supplier =>
+            {
+                return ConvertToSupplierDto(supplier);
+            });
+
+            return supplierDtoList;
+        }
+
+        public async Task<SupplierDto> GetSupplierByIdAsync(Guid supplierId, CancellationToken cancellationToken)
+        {
+            var supplier = await _supplierRepository.GetByIdAsync(supplierId, cancellationToken);
+
+            var supplierDto = ConvertToSupplierDto(supplier);
+
+            return supplierDto;
+        }
+
+        private SupplierDto ConvertToSupplierDto(Supplier supplier)
+        {
+            var supplierDto = new SupplierDto
+            {
+                Id = supplier.SupplierId,
+            };
+            return supplierDto;
+        }
+    }
+}