diff --git a/README.md b/README.md
index fa387b9e..1b02dbd7 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,7 @@ Quick Start Guide 👉 [https://docs.httpsms.com](https://docs.httpsms.com)
   - [Webhook](#webhook)
   - [Back Pressure](#back-pressure)
   - [Message Expiration](#message-expiration)
+  - [International Phone Number Support](#international-phone-number-support)
 - [API Clients](#api-clients)
 - [Flows](#flows)
   - [Sending an SMS Message](#sending-an-sms-message)
@@ -112,6 +113,24 @@ Sometimes it happens that the phone doesn't get the push notification in time an
 possible to set a timeout for which a message is valid and if a message becomes expired after the timeout elapses, you
 will be notified.
 
+### International Phone Number Support
+
+httpSMS supports phone numbers from multiple countries and regions. Phone numbers can be provided in the following formats:
+
+- **International E.164 format** (recommended): `+33612345678`, `+18005550100`, `+237671234567`
+- **National format**: `0612345678` (France), `0123456789` (France)
+- **Without leading zeros**: Numbers without country code prefix will be automatically detected if they match common formats
+
+The system automatically converts phone numbers to the standard E.164 format for consistent handling across different regions.
+
+**Supported countries include:**
+- 🇫🇷 France (e.g., `+33612345678` or `0612345678`)
+- 🇺🇸 United States (e.g., `+18005550100`)
+- 🇬🇧 United Kingdom (e.g., `+441234567890`)
+- 🇩🇪 Germany, 🇪🇸 Spain, 🇮🇹 Italy
+- 🇨🇲 Cameroon, 🇳🇬 Nigeria, 🇿🇦 South Africa
+- And many more...
+
 ## API Clients
 
 - [x] Go: https://github.com/NdoleStudio/httpsms-go
diff --git a/api/pkg/requests/request.go b/api/pkg/requests/request.go
index 851137d1..a9c34362 100644
--- a/api/pkg/requests/request.go
+++ b/api/pkg/requests/request.go
@@ -11,6 +11,10 @@ import (
 	"github.com/nyaruka/phonenumbers"
 )
 
+// commonRegionCodes are the region codes tried when parsing phone numbers in national format
+// These regions are attempted in order when UNKNOWN_REGION parsing fails
+var commonRegionCodes = []string{"FR", "US", "GB", "DE", "ES", "IT", "CM", "NG", "ZA"}
+
 type request struct{}
 
 func (input *request) sanitizeAddresses(value []string) []string {
@@ -23,12 +27,29 @@ func (input *request) sanitizeAddresses(value []string) []string {
 
 func (input *request) sanitizeAddress(value string) string {
 	value = strings.TrimSpace(value)
-	if !strings.HasPrefix(value, "+") && input.isDigits(value) && len(value) > 9 {
-		value = "+" + value
-	}
-
+	
+	// Try parsing with UNKNOWN_REGION first (works for international format)
 	if number, err := phonenumbers.Parse(value, phonenumbers.UNKNOWN_REGION); err == nil {
 		value = phonenumbers.Format(number, phonenumbers.E164)
+		return value
+	}
+
+	// If value doesn't start with + and has more than 9 digits, try adding +
+	if !strings.HasPrefix(value, "+") && input.isDigits(value) && len(value) > 9 && !strings.HasPrefix(value, "0") {
+		testValue := "+" + value
+		if number, err := phonenumbers.Parse(testValue, phonenumbers.UNKNOWN_REGION); err == nil {
+			value = phonenumbers.Format(number, phonenumbers.E164)
+			return value
+		}
+	}
+
+	// If UNKNOWN_REGION fails, try common region codes for national formats
+	// This supports phone numbers without country code (e.g., French "0612345678")
+	for _, region := range commonRegionCodes {
+		if number, err := phonenumbers.Parse(value, region); err == nil && phonenumbers.IsValidNumber(number) {
+			value = phonenumbers.Format(number, phonenumbers.E164)
+			break
+		}
 	}
 
 	return value
diff --git a/api/pkg/validators/validator.go b/api/pkg/validators/validator.go
index bc7111e8..57da57fd 100644
--- a/api/pkg/validators/validator.go
+++ b/api/pkg/validators/validator.go
@@ -29,12 +29,12 @@ func init() {
 	govalidator.AddCustomRule(phoneNumberRule, func(field string, rule string, message string, value interface{}) error {
 		phoneNumber, ok := value.(string)
 		if !ok {
-			return fmt.Errorf("The %s field must be a valid E.164 phone number in the international format e.g +18005550100", field)
+			return fmt.Errorf("The %s field must be a valid E.164 phone number in the international format e.g +18005550100 or +33612345678", field)
 		}
 
 		_, err := phonenumbers.Parse(phoneNumber, phonenumbers.UNKNOWN_REGION)
 		if err != nil {
-			return fmt.Errorf("The %s field must be a valid E.164 phone number in the international format e.g +18005550100", field)
+			return fmt.Errorf("The %s field must be a valid E.164 phone number in the international format e.g +18005550100 or +33612345678", field)
 		}
 
 		return nil
@@ -49,7 +49,7 @@ func init() {
 		for index, number := range phoneNumbers {
 			_, err := phonenumbers.Parse(number, phonenumbers.UNKNOWN_REGION)
 			if err != nil {
-				return fmt.Errorf("The %s field in index [%d] must be a valid E.164 phone number in the international format e.g +18005550100", field, index)
+				return fmt.Errorf("The %s field in index [%d] must be a valid E.164 phone number in the international format e.g +18005550100 or +33612345678", field, index)
 			}
 		}