diff --git a/internal/api/validator.go b/internal/api/validator.go
index 6af1eab..e3be9a2 100644
--- a/internal/api/validator.go
+++ b/internal/api/validator.go
@@ -1,6 +1,7 @@
 package api
 
 import (
+	"fmt"
 	"net/http"
 	"regexp"
 
@@ -12,10 +13,40 @@ type CustomValidator struct {
 	validator *validator.Validate
 }
 
-func (validator *CustomValidator) Validate(i any) error {
-	if err := validator.validator.Struct(i); err != nil {
-		return echo.NewHTTPError(http.StatusBadRequest, err.Error())
+func (v *CustomValidator) Validate(i any) error {
+	if err := v.validator.Struct(i); err != nil {
+		if validationErrors, ok := err.(validator.ValidationErrors); ok {
+			errors := make(map[string]string)
+
+			for _, ve := range validationErrors {
+				field := ve.Field()
+				tag := ve.Tag()
+
+				var msg string
+
+				switch tag {
+				case "required":
+					msg = fmt.Sprintf("%s is required!", field)
+				case "email":
+					msg = fmt.Sprintf("%s must be a valid email!", field)
+				case "alpha":
+					msg = fmt.Sprintf("%s must only contain alphabetic characters!", field)
+				case "e164":
+					msg = fmt.Sprintf("%s must be a valid phone number in e164 format!", field)
+				case "password":
+					msg = fmt.Sprintf("%s must have at lease one uppercase, one lowercase, one number and one special character!", field)
+				case "eqcsfield":
+					msg = fmt.Sprintf("%s must be the same as %s!", field, ve.Param())
+				default:
+					msg = fmt.Sprintf("%s is not valid!", field)
+				}
+
+				errors[field] = msg
+			}
+			return echo.NewHTTPError(http.StatusBadRequest, errors)
+		}
 	}
+
 	return nil
 }
 
diff --git a/internal/models/user.go b/internal/models/user.go
index fc58a2b..990347c 100644
--- a/internal/models/user.go
+++ b/internal/models/user.go
@@ -1,6 +1,8 @@
 package models
 
 import (
+	"strings"
+
 	"github.com/hazemKrimi/crimson-vault/internal/types"
 )
 
@@ -77,7 +79,7 @@ func (db *DB) UpdateUserSecurityDetails(id int, body types.UpdateUserSecurityDet
 	}
 
 	result = db.instance.Model(user).Updates(types.User{
-		Username: body.Username,
+		Username: strings.ToLower(body.Username),
 		Password: body.Password,
 	})
 
diff --git a/internal/types/client.go b/internal/types/client.go
index 851dfcd..b0640bb 100644
--- a/internal/types/client.go
+++ b/internal/types/client.go
@@ -21,21 +21,21 @@ type Client struct {
 }
 
 type CreateClientRequestBody struct {
-	Name       string `json:"name" validate:"required"`
+	Name       string `json:"name" validate:"required,alpha"`
 	FiscalCode string `json:"fiscalCode"`
 	Address    string `json:"address" validate:"required"`
 	Zip        string `json:"zip" validate:"required"`
-	Country    string `json:"country" validate:"required"`
+	Country    string `json:"country" validate:"required,alpha"`
 	Phone      string `json:"phone" validate:"required,e164"`
 	Email      string `json:"email" validate:"required,email"`
 }
 
 type UpdateClientRequestBody struct {
-	Name       string `json:"name"`
+	Name       string `json:"name" validate:"omitempty,alpha"`
 	FiscalCode string `json:"fiscalCode"`
 	Address    string `json:"address"`
 	Zip        string `json:"zip"`
-	Country    string `json:"country"`
+	Country    string `json:"country" validate:"omitempty,alpha"`
 	Phone      string `json:"phone" validate:"omitempty,e164"`
 	Email      string `json:"email" validate:"omitempty,email"`
 }
diff --git a/internal/types/user.go b/internal/types/user.go
index 567c3d1..8233d66 100644
--- a/internal/types/user.go
+++ b/internal/types/user.go
@@ -24,21 +24,21 @@ type User struct {
 }
 
 type CreateUserRequestBody struct {
-	Name       string `json:"name" validate:"required"`
+	Name       string `json:"name" validate:"required,alpha"`
 	FiscalCode string `json:"fiscalCode" validate:"required"`
 	Address    string `json:"address" validate:"required"`
 	Zip        string `json:"zip" validate:"required"`
-	Country    string `json:"country" validate:"required"`
+	Country    string `json:"country" validate:"required,alpha"`
 	Phone      string `json:"phone" validate:"required,e164"`
 	Email      string `json:"email" validate:"required,email"`
 }
 
 type UpdateUserRequestBody struct {
-	Name       string `json:"name"`
+	Name       string `json:"name" validate:"omitempty,alpha"`
 	FiscalCode string `json:"fiscalCode"`
 	Address    string `json:"address"`
 	Zip        string `json:"zip"`
-	Country    string `json:"country"`
+	Country    string `json:"country" validate:"omitempty,alpha"`
 	Phone      string `json:"phone" validate:"omitempty,e164"`
 	Email      string `json:"email" validate:"omitempty,email"`
 }