diff --git a/backend/src/modules/fuel-requests/fuelRequest.interface.ts b/backend/src/modules/fuel-requests/fuelRequest.interface.ts
index 09edab7..cc01fc7 100644
--- a/backend/src/modules/fuel-requests/fuelRequest.interface.ts
+++ b/backend/src/modules/fuel-requests/fuelRequest.interface.ts
@@ -1,8 +1,8 @@
-import { ObjectId } from "mongoose";
+import { Types } from "mongoose";
 
 export interface IFuelRequest {
 
-    _id?: ObjectId;
+    _id?: Types.ObjectId;
 
     requestNumber: string;
 
@@ -14,13 +14,13 @@ export interface IFuelRequest {
 
     routeId: number;
 
-    fuelPumpId: ObjectId;
+    fuelPumpId: Types.ObjectId;
 
-    fuelTypeId: ObjectId;
+    fuelTypeId: Types.ObjectId;
 
-    createdBy: ObjectId;
+    createdBy: Types.ObjectId;
 
-    authorizedBy?: ObjectId;
+    authorizedBy?: Types.ObjectId;
 
     gallonQuantity: number;
 
@@ -34,7 +34,7 @@ export interface IFuelRequest {
 
     distanceTraveled?: number;
 
-    pumpReading?: ObjectId;
+    pumpReading?: Types.ObjectId;
 
     pumpDifference?: number;
 
diff --git a/backend/src/modules/fuel-requests/fuelRequest.model.ts b/backend/src/modules/fuel-requests/fuelRequest.model.ts
index fd26306..6f55a58 100644
--- a/backend/src/modules/fuel-requests/fuelRequest.model.ts
+++ b/backend/src/modules/fuel-requests/fuelRequest.model.ts
@@ -30,12 +30,14 @@ const fuelRequestSchema = new mongoose.Schema({
 
     fuelPumpId:{
         type:mongoose.Schema.Types.ObjectId,
-        ref:"FuelPump"
+        ref:"FuelPump",
+        required:true
     },
 
     fuelTypeId:{
         type:mongoose.Schema.Types.ObjectId,
-        ref:"FuelType"
+        ref:"FuelType",
+        required:true
     },
 
     createdBy:{
diff --git a/backend/src/modules/fuel-requests/fuelRequest.service.ts b/backend/src/modules/fuel-requests/fuelRequest.service.ts
index b2b7420..0812462 100644
--- a/backend/src/modules/fuel-requests/fuelRequest.service.ts
+++ b/backend/src/modules/fuel-requests/fuelRequest.service.ts
@@ -40,6 +40,16 @@ export class FuelRequestService {
     async create (
         data:IFuelRequest
     ){
+        ///Validar kilometraje
+        if(data.currentMileage < data.previousMileage) {
+            throw new Error ("El kilometraje no puede ser menor que el anterior");
+        }
+
+        //Validar que los galones sean mayor a 0
+        if(data.gallonQuantity <= 0){
+            throw new Error ("La cantidad de galones debe ser mayor que 0");
+        }
+
         //Generar número automático
         data.requestNumber = generateRequestNumber();
 
@@ -56,7 +66,14 @@ export class FuelRequestService {
         const request = new fuelRequestModel(data);
 
         //Guardar en DB
-        return await request.save();
+        const fuelRequest = await request.save();
+
+        //Validaciones automáticas
+        await this.detectAnomalies(
+            fuelRequest
+        );
+
+        return fuelRequest;
 
     }
 
@@ -64,33 +81,45 @@ export class FuelRequestService {
         id:string,
         data:Partial<IFuelRequest>
     ){
-        //Recalcular distancia
-        if(data.currentMileage !== undefined &&
-            data.previousMileage !== undefined
-        ){
-            data.distanceTraveled =
-            data.currentMileage -
-            data.previousMileage;
+        //Buscar la requisición actual
+        const request = await fuelRequestModel.findById(id);
+
+        if(!request){
+            return null;
         }
 
-        //Recalcular monto
-        if(
-            data.gallonQuantity !== undefined &&
-            data.pricePerGallon !== undefined
-        ){
-            data.totalAmount =
-            data.gallonQuantity *
-            data.pricePerGallon;
+        const previousMileage = data.previousMileage ?? request.previousMileage;
+
+        const currentMileage = data.currentMileage ?? request.currentMileage;
+
+        const gallonQuantity = data.gallonQuantity ?? request.gallonQuantity;
+
+        const pricePerGallon = data.pricePerGallon ?? request.pricePerGallon;
+
+        //Recalcular distancia recorrida
+        data.distanceTraveled = currentMileage - previousMileage;
+
+        //Validar kilometraje
+
+        if(data.distanceTraveled < 0){
+            throw new Error("El kilometraje actual no puede ser menor que el anterior");
         }
 
-        return await fuelRequestModel
-        .findByIdAndUpdate(
+        //Recalcular monto total
+
+        data.totalAmount = gallonQuantity * pricePerGallon;
+
+        //Actualizar la requisición
+        const updateRequest = await fuelRequestModel.findByIdAndUpdate(
             id,
             data,
             {
                 new:true
             }
         );
+
+        return updateRequest;
+
     }
 
     //Eliminar requisición
@@ -198,7 +227,7 @@ export class FuelRequestService {
         data:any
     ){
         const vehicleConfig = await vehiclesConfigModel.findOne({
-            vehicleid:data.vehicleId
+            vehicleId:data.vehicleId
         });
 
         //Sino existe configuración no validar
@@ -210,12 +239,12 @@ export class FuelRequestService {
 
         if(
             data.gallonQuantity >
-            vehicleConfig.tankcapacity
+            vehicleConfig.tankCapacity
         ){
             await this.createAnomaly(
                 data,
                 "CONSUMO ELEVADO",
-                `Se solicitaron ${data.gallonQuantity} galones, pero la capacidad del tanque es de ${vehicleConfig.tankcapacity} galones.`
+                `Se solicitaron ${data.gallonQuantity} galones, pero la capacidad del tanque es de ${vehicleConfig.tankCapacity} galones.`
             )
         }
     }