diff --git a/src/Somnia.GuestLog/GuestConsts.cs b/src/Somnia.GuestLog/GuestConsts.cs
index 601e684..ec4c06c 100644
--- a/src/Somnia.GuestLog/GuestConsts.cs
+++ b/src/Somnia.GuestLog/GuestConsts.cs
@@ -32,6 +32,10 @@ public static class GuestConsts
     public const string DocumentType_NIE = "NIE";
     public const string DocumentType_PASSPORT = "PASSPORT";
 
+    public const string GenderOptions_MALE = "M";
+    public const string GenderOptions_FEMALE = "F";
+    public const string GenderOptions_OTHER = "O";
+
     public const int GuestDocument_FirstVersion = 1;
 
 
diff --git a/src/Somnia.GuestLog/Models/Configuration/StayExportSpainParteViajerosConfig.cs b/src/Somnia.GuestLog/Models/Configuration/StayExportSpainParteViajerosConfig.cs
new file mode 100644
index 0000000..28e9393
--- /dev/null
+++ b/src/Somnia.GuestLog/Models/Configuration/StayExportSpainParteViajerosConfig.cs
@@ -0,0 +1,9 @@
+namespace Somnia.GuestLog.Models.Configuration;
+
+public class StayExportSpainParteViajerosConfig
+{
+    public const string SectionName = "StayExportSpainParteViajeros";
+
+    public bool InternetAvailable { get; set; } = false;
+    public string? CodigoEstablecimiento { get; set; }
+}
diff --git a/src/Somnia.GuestLog/Program.cs b/src/Somnia.GuestLog/Program.cs
index 134890f..44b56c4 100644
--- a/src/Somnia.GuestLog/Program.cs
+++ b/src/Somnia.GuestLog/Program.cs
@@ -79,6 +79,8 @@ builder.Services.AddOptions<AddressQueryConfig>()
     .Bind(builder.Configuration.GetSection(AddressQueryConfig.SectionName));
 builder.Services.AddOptions<StayExportConfig>()
     .Bind(builder.Configuration.GetSection(StayExportConfig.SectionName));
+builder.Services.AddOptions<StayExportSpainParteViajerosConfig>()
+    .Bind(builder.Configuration.GetSection(StayExportSpainParteViajerosConfig.SectionName));
 
 var app = builder.Build();
 
diff --git a/src/Somnia.GuestLog/Services/SpainCodigoMunicipio/SpainCodigoMunicipioCatastroService.cs b/src/Somnia.GuestLog/Services/SpainCodigoMunicipio/SpainCodigoMunicipioCatastroService.cs
index 6058a5e..c7109ee 100644
--- a/src/Somnia.GuestLog/Services/SpainCodigoMunicipio/SpainCodigoMunicipioCatastroService.cs
+++ b/src/Somnia.GuestLog/Services/SpainCodigoMunicipio/SpainCodigoMunicipioCatastroService.cs
@@ -13,12 +13,26 @@ public class SpainCodigoMunicipioCatastroService(
     private const string Api_Param_Provincia = "Provincia";
     private const string Api_Param_Municipio = "Municipio";
 
+
+    //Result Cache.
+    readonly Dictionary<(string provincia, string municipio), string> codigoMunicipioCache = [];
+
+
     public async Task<string?> GetCodigoMunicipioAsync(string municipio, string province)
     {
+        var cacheKey = (province.ToUpper(), municipio.ToUpper());
+
+        //Try get from cache.
+        if (codigoMunicipioCache.TryGetValue(cacheKey, out string? cacheCode))
+        {
+            logger.LogInformation("SpainCodigoMunicipioCatastroService - Municipio found in cache for: '{key}'", cacheKey);
+            return cacheCode;
+        }
+
         try
         {
             string uri = GetRequestUri(municipio, province);
-            logger.LogInformation("SpainCodigoMunicipioCatastroService - Getting municipios with query: '{addr}'", uri);
+            logger.LogInformation("SpainCodigoMunicipioCatastroService - Getting municipios from API with query: '{addr}'", uri);
 
             var httpClient = httpFactory.CreateClient();
             using var rsStream = await httpClient.GetStreamAsync(uri);
@@ -49,7 +63,10 @@ public class SpainCodigoMunicipioCatastroService(
                 return null;
             }
 
-            return $"{codIne.codigoProvincia}{codIne.codigoMunicipio}";
+            string finalCode = $"{codIne.codigoProvincia}{codIne.codigoMunicipio}";
+
+            codigoMunicipioCache.Add(cacheKey, finalCode);
+            return finalCode;
         }
         catch (Exception ex)
         {
diff --git a/src/Somnia.GuestLog/Services/StayExport/StayExportProviderSpainParteViajeros.cs b/src/Somnia.GuestLog/Services/StayExport/StayExportProviderSpainParteViajeros.cs
index 15c47ee..68fc1be 100644
--- a/src/Somnia.GuestLog/Services/StayExport/StayExportProviderSpainParteViajeros.cs
+++ b/src/Somnia.GuestLog/Services/StayExport/StayExportProviderSpainParteViajeros.cs
@@ -1,20 +1,399 @@
+using System.Diagnostics;
+using System.Xml.Serialization;
+using FluentValidation;
+using Microsoft.Extensions.Options;
 using Somnia.GuestLog.Enums.Models;
+using Somnia.GuestLog.Models.Configuration;
 using Somnia.GuestLog.Models.DTOs;
+using Somnia.GuestLog.Services.SpainCodigoMunicipio;
 
 namespace Somnia.GuestLog.Services.StayExport;
 
 public class StayExportProviderSpainParteViajeros(
-
+    ILogger<StayExportProviderSpainParteViajeros> logger,
+    ISpainCodigoMunicipioService codigoMunicipioService,
+    IOptions<StayExportSpainParteViajerosConfig> configOptions
 ) : IStayExportFormatProvider
 {
     private const string fileExtension = "xml";
 
+    private const string PersonRole = "VI";
+    private const string PersonRelation = "OT";
+
+    private const string PersonTipoDoc_NIF = "NIF";
+    private const string PersonTipoDoc_NIE = "NIE";
+    private const string PersonTipoDoc_PAS = "PAS";
+    private const string PersonTipoDoc_OTRO = "OTRO";
+
+    private const string PersonDireccionPais_ESP = "ESP";
+
+    private const string XmlNamespace_Peticion = "http://www.neg.hospedajes.mir.es/altaParteHospedaje";
+
+    private readonly StayExportSpainParteViajerosConfig config = configOptions.Value;
+
     public StayExportFormat GetFormat() => StayExportFormat.SpainParteViajeros;
     public string GetFilename(DateTime exportTime)
         => $"{Enum.GetName(GetFormat())}_{exportTime.ToFileTimeUtc()}.{fileExtension}";
 
-    public Task<StayExportFileResult> ExportDataAsync(IEnumerable<StayEntryDTO> stayList, Stream dataStream)
+    public async Task<StayExportFileResult> ExportDataAsync(IEnumerable<StayEntryDTO> stayList, Stream dataStream)
     {
-        throw new NotImplementedException();
+        if (string.IsNullOrEmpty(config.CodigoEstablecimiento))
+        {
+            logger.LogError("StayExportProviderSpainParteViajeros - Config error: CodigoEstablecimiento is not configured!");
+            return StayExportFileResult.ExportError;
+        }
+
+        if (!stayList.Any())
+        {
+            return StayExportFileResult.NoData;
+        }
+
+        ComunicacionValidator comunicacionValidator = new();
+
+        List<Comunicacion> comunicacionsList = [];
+        foreach (StayEntryDTO stay in stayList)
+        {
+            (Comunicacion? comunicacion, string code) = await GetComunicacionFromStay(stay);
+            if (comunicacion == null)
+            {
+                logger.LogWarning("StayExportProviderSpainParteViajeros - Stay (ID: {id}) can't be exported: Code: {code}", stay.Id, code);
+                continue;
+            }
+
+            var errors = comunicacionValidator.Validate(comunicacion);
+            if (!errors.IsValid)
+            {
+                logger.LogWarning("StayExportProviderSpainParteViajeros - Stay (ID: {id}) is invalid: Errors: {errors}", stay.Id, errors.Errors);
+                continue;
+            }
+
+            comunicacionsList.Add(comunicacion);
+            logger.LogInformation("StayExportProviderSpainParteViajeros - Stay (ID: {id}) Exported OK", stay.Id);
+        }
+
+        Peticion peticion = new()
+        {
+            solicitud = new()
+            {
+                codigoEstablecimiento = config.CodigoEstablecimiento,
+                comunicacion = comunicacionsList,
+            }
+        };
+
+        XmlSerializer serializer = new(typeof(Peticion));
+        serializer.Serialize(dataStream, peticion);
+
+        return StayExportFileResult.OK;
     }
+
+    #region Internal Methods
+
+    private async Task<(Comunicacion? comunicacion, string code)> GetComunicacionFromStay(StayEntryDTO stay)
+    {
+        Debug.Assert(stay.Id != null
+            && stay.DateIn != null
+            && stay.DateOut != null
+            && stay.GuestDocuments != null
+        );
+
+        //Call Fn to validate Stay.
+
+        Contrato contrato = new()
+        {
+            referencia = stay.Id.Value.ToString(),
+            fechaContrato = stay.DateIn.Value.Date,
+            fechaEntrada = stay.DateIn.Value,
+            fechaSalida = stay.DateOut.Value,
+            internet = config.InternetAvailable,
+            numHabitaciones = stay.RoomCount ?? -1,
+            numPersonas = stay.GuestDocuments.Count,
+            pago = new()
+            {
+                tipoPago = GetTipoPagoFromStay(stay)!
+            }
+        };
+
+        List<Persona> personasList = [];
+        foreach (GuestDocumentDTO doc in stay.GuestDocuments)
+        {
+            Direccion dir = new()
+            {
+                direccion = doc.Address!,
+                codigoPostal = doc.ZipCode!,
+                pais = doc.AddressCountry!,
+            };
+
+            //Get Municipio given current country.
+            if (doc.AddressCountry != PersonDireccionPais_ESP)
+            {
+                List<string?> addressParts = [doc.AddressCity, doc.AddressProvince, doc.AddressState];
+                dir.nombreMunicipio = string.Join(", ", addressParts.Where(p => !string.IsNullOrEmpty(p)));
+            }
+            if (doc.AddressCountry == PersonDireccionPais_ESP)
+            {
+                dir.codigoMunicipio = await GetMunicipioFromGuestAddressAsync(doc);
+                if (dir.codigoMunicipio == null)
+                {
+                    return (
+                        comunicacion: null,
+                        code: "NoCodigoMunicipio"
+                    );
+                }
+            }
+
+            Persona persona = new()
+            {
+                rol = PersonRole,
+                nombre = doc.Name!,
+                apellido1 = doc.Surname!,
+                apellido2 = doc.Surname2,
+                tipoDocumento = GetTipoDocumentoFromGuest(doc)!,
+                numeroDocumento = doc.DocumentNum!,
+                soporteDocumento = doc.SupportNum,
+                fechaNacimiento = doc.BirthDate?.Date ?? DateTime.MaxValue,
+                nacionalidad = doc.Nationality!,
+                sexo = GetSexoFromGuest(doc)!,
+                telefono = doc.PhoneNumber,
+                correo = doc.EmailAddress,
+                parentesco = PersonRelation,
+                direccion = dir,
+            };
+            personasList.Add(persona);
+        }
+
+        return (
+            comunicacion: new()
+            {
+                contrato = contrato,
+                persona = personasList
+            },
+            code: "OK");
+    }
+
+    private static string? GetTipoDocumentoFromGuest(GuestDocumentDTO doc)
+    {
+        return doc.DocumentType switch
+        {
+            GuestConsts.DocumentType_DNI => PersonTipoDoc_NIF,
+            GuestConsts.DocumentType_NIE => PersonTipoDoc_NIE,
+            GuestConsts.DocumentType_PASSPORT => PersonTipoDoc_PAS,
+            null => null,
+            _ => PersonTipoDoc_OTRO
+        };
+    }
+
+    private static string? GetSexoFromGuest(GuestDocumentDTO doc)
+    {
+        return doc.Gender switch
+        {
+            GuestConsts.GenderOptions_MALE => "H",
+            GuestConsts.GenderOptions_FEMALE => "F",
+            null => null,
+            _ => "O"
+        };
+    }
+
+    private static string? GetTipoPagoFromStay(StayEntryDTO stay)
+    {
+        return stay.PaymentMethod;
+    }
+
+    private async Task<string?> GetMunicipioFromGuestAddressAsync(GuestDocumentDTO doc)
+    {
+        if (string.IsNullOrEmpty(doc.AddressCity) || string.IsNullOrEmpty(doc.AddressProvince))
+        {
+            return null;
+        }
+
+        //Get codMunicipio from API.
+        return await codigoMunicipioService.GetCodigoMunicipioAsync(doc.AddressCity, doc.AddressProvince);
+    }
+
+    #endregion
+
+    #region Validator
+
+    private sealed class ComunicacionValidator : AbstractValidator<Comunicacion>
+    {
+        //TODO: Validate values in list for: Pago.tipoPago, Persona.sexo, Persona.tipoDocumento
+
+        public ComunicacionValidator()
+        {
+            RuleFor(comm => comm.contrato)
+                .NotNull()
+                .ChildRules(contrato =>
+                {
+                    contrato.RuleFor(p => p.referencia)
+                        .NotEmpty()
+                        .MaximumLength(50);
+
+                    contrato.RuleFor(p => p.fechaEntrada)
+                        .LessThan(p => p.fechaSalida);
+
+                    contrato.RuleFor(p => p.fechaSalida)
+                        .GreaterThan(p => p.fechaEntrada);
+
+                    contrato.RuleFor(p => p.numHabitaciones)
+                        .GreaterThanOrEqualTo(0);
+
+                    //BLOQUE PAGO
+                    contrato.RuleFor(p => p.pago)
+                        .ChildRules(e =>
+                        {
+                            e.RuleFor(p => p.tipoPago)
+                                .NotEmpty();
+                        });
+                });
+
+            RuleForEach(comm => comm.persona)
+                .ChildRules(person =>
+                {
+                    person.RuleFor(p => p.rol)
+                        .Equal(PersonRole);
+                    person.RuleFor(p => p.nombre)
+                        .NotEmpty()
+                        .MaximumLength(50);
+                    person.RuleFor(p => p.apellido1)
+                        .NotEmpty()
+                        .MaximumLength(50);
+                    person.RuleFor(p => p.apellido2)
+                        .MaximumLength(50);
+                    person.RuleFor(p => p.tipoDocumento)
+                        .NotEmpty()
+                        .MaximumLength(5);
+                    person.RuleFor(p => p.numeroDocumento)
+                        .NotEmpty()
+                        .MaximumLength(15);
+                    person.RuleFor(p => p.soporteDocumento)
+                        .NotEmpty()
+                        .When(p => p.tipoDocumento == PersonTipoDoc_NIF || p.tipoDocumento == PersonTipoDoc_NIE);
+                    person.RuleFor(p => p.fechaNacimiento)
+                        .NotEmpty();
+                    person.RuleFor(p => p.sexo)
+                        .MaximumLength(1);
+                    person.RuleFor(p => p.telefono)
+                        .MaximumLength(20);
+                    person.RuleFor(p => p.correo)
+                        .MaximumLength(250);
+
+                    person.RuleFor(p => p.direccion)
+                        .ChildRules(d =>
+                        {
+                            d.RuleFor(p => p.direccion)
+                                .NotEmpty()
+                                .MaximumLength(100);
+                            d.RuleFor(p => p.codigoMunicipio)
+                                .NotEmpty()
+                                .When(p => p.pais == PersonDireccionPais_ESP)
+                                .MaximumLength(5);
+                            d.RuleFor(p => p.nombreMunicipio)
+                                .NotEmpty()
+                                .When(p => p.pais != PersonDireccionPais_ESP)
+                                .MaximumLength(100);
+                            d.RuleFor(p => p.codigoMunicipio)
+                                .NotEmpty()
+                                .MaximumLength(20);
+                            d.RuleFor(p => p.pais)
+                                .NotEmpty()
+                                .Length(3);
+                        });
+                });
+
+            RuleForEach(comm => comm.persona)
+                .Must(p => !string.IsNullOrEmpty(p.telefono) || !string.IsNullOrEmpty(p.correo))
+                .WithMessage($"It's required to have at least one of the following fields: '{nameof(Persona.telefono)}', '{nameof(Persona.correo)}'");
+        }
+    }
+
+    #endregion
+
+    #region Export Data Classes
+
+    [XmlRoot(ElementName = "peticion", Namespace = XmlNamespace_Peticion)]
+    public class Peticion
+    {
+        public required Solicitud solicitud;
+    }
+
+    [XmlRoot(ElementName = "solicitud")]
+    public class Solicitud
+    {
+        public required string codigoEstablecimiento;
+        public required List<Comunicacion> comunicacion;
+    }
+
+    [XmlRoot(ElementName = "comunicacion")]
+    public class Comunicacion
+    {
+        public required Contrato contrato;
+        public required List<Persona> persona;
+    }
+
+    [XmlRoot(ElementName = "contrato")]
+    public class Contrato
+    {
+        public required string referencia;
+
+        [XmlElement(DataType = "date")]
+        public required DateTime fechaContrato;
+
+        [XmlElement(DataType = "dateTime")]
+        public required DateTime fechaEntrada;
+
+        [XmlElement(DataType = "dateTime")]
+        public required DateTime fechaSalida;
+
+        public required int numPersonas;
+        public int? numHabitaciones;
+        public bool? internet;
+
+        //BLOQUE PAGO
+        public required Pago pago;
+    }
+
+    [XmlRoot(ElementName = "persona")]
+    public class Persona
+    {
+        public required string rol;
+        public required string nombre;
+        public required string apellido1;
+        public string? apellido2;
+        public required string tipoDocumento;
+        public required string numeroDocumento;
+        public string? soporteDocumento;
+
+        [XmlElement(DataType = "date")]
+        public required DateTime fechaNacimiento;
+        public required string nacionalidad;
+        public required string sexo;
+
+        public string? telefono;
+        public string? correo;
+        public required string parentesco;
+
+        // BLOQUE DIRECCION
+        public required Direccion direccion;
+    }
+
+    public class Pago
+    {
+        public required string tipoPago;
+
+        // [XmlElement(DataType = "date")]
+        // public required DateTime fechaPago;
+        public string? medioPago;
+        public string? titular;
+        public string? caducidadTarjeta;
+    }
+
+    public class Direccion
+    {
+        public required string direccion;
+        public string? codigoMunicipio;
+        public string? nombreMunicipio;
+        public required string codigoPostal;
+        public required string pais;
+    }
+
+    #endregion
 }
\ No newline at end of file
diff --git a/src/Somnia.GuestLog/appsettings.json b/src/Somnia.GuestLog/appsettings.json
index ac9b3f2..f557d9d 100644
--- a/src/Somnia.GuestLog/appsettings.json
+++ b/src/Somnia.GuestLog/appsettings.json
@@ -25,5 +25,9 @@
     "EnableStayExport": true,
     "ExportStorageConnectionString": "disk://path=/SomniaGuestLog/StayExportFiles",
     "UseSubdirectoryByFormat": true
+  },
+  "StayExportSpainParteViajeros": {
+    "InternetAvailable": true,
+    "CodigoEstablecimiento": ""
   }
 }
\ No newline at end of file