diff --git a/htdocs/admin/company.php b/htdocs/admin/company.php
index a0c935413f367..0a7770bcc3dc5 100644
--- a/htdocs/admin/company.php
+++ b/htdocs/admin/company.php
@@ -6,6 +6,7 @@
  * Copyright (C) 2011-2017	Philippe Grand			<philippe.grand@atoo-net.com>
  * Copyright (C) 2015		Alexandre Spangaro		<aspangaro@open-dsi.fr>
  * Copyright (C) 2017       Rui Strecht			    <rui.strecht@aliartalentos.com>
+ * Copyright (C) 2023       Nick Fragoulis
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -233,6 +234,14 @@
 		dolibarr_set_const($db, "MAIN_INFO_LOCALTAX_CALC2", GETPOST("clt2", 'aZ09'), 'chaine', 0, '', $conf->entity);
 	}
 
+	// Credentials for AADE webservices, applicable only for Greece
+	if ($mysoc->country_code == 'GR') {
+		dolibarr_set_const($db, "MYDATA_AADE_USER", GETPOST("MYDATA_AADE_USER", 'alpha'), 'chaine', 0, '', $conf->entity);
+		dolibarr_set_const($db, "MYDATA_AADE_KEY", GETPOST("MYDATA_AADE_KEY", 'alpha'), 'chaine', 0, '', $conf->entity);
+		dolibarr_set_const($db, "AADE_WEBSERVICE_USER", GETPOST("AADE_WEBSERVICE_USER", 'alpha'), 'chaine', 0, '', $conf->entity);
+		dolibarr_set_const($db, "AADE_WEBSERVICE_KEY", GETPOST("AADE_WEBSERVICE_KEY", 'alpha'), 'chaine', 0, '', $conf->entity);
+	}
+
 	// Remove constant MAIN_INFO_SOCIETE_SETUP_TODO_WARNING
 	dolibarr_del_const($db, "MAIN_INFO_SOCIETE_SETUP_TODO_WARNING", $conf->entity);
 
@@ -847,6 +856,41 @@
 
 print "</table>";
 
+// AADE webservices credentials, applicable only for Greece
+if ($mysoc->country_code == 'GR') {
+	print load_fiche_titre($langs->trans("AADEWebserviceCredentials"), '', '');
+	print '<table class="noborder centpercent editmode">';
+	print '<tr class="liste_titre">';
+	print '<td>'.$langs->trans("AccountParameter").'</td>';
+	print '<td>'.$langs->trans("Value").'</td>';
+	print '<td></td>';
+	print "</tr>\n";
+
+	print '<tr class="oddeven"><td>';
+	print '<span class="titlefield fieldrequired">'.$langs->trans("MYDATA_AADE_USER").'</span></td><td>';
+	print '<input class="minwidth300" type="text" name="MYDATA_AADE_USER" value="'.getDolGlobalString('MYDATA_AADE_USER').'"';
+	print '</td><td></td></tr>';
+
+	print '<tr class="oddeven"><td>';
+	print '<span class="titlefield fieldrequired">'.$langs->trans("MYDATA_AADE_KEY").'</span></td><td>';
+	print '<input class="minwidth300" type="text" name="MYDATA_AADE_KEY="'.getDolGlobalString('MYDATA_AADE_KEY').'"';
+	print '</td><td></td></tr>';
+
+	print '<tr class="oddeven"><td>';
+	print '<span class="titlefield fieldrequired">'.$langs->trans("AADE_WEBSERVICE_USER").'</span></td><td>';
+	print '<input class="minwidth300" type="text" name="AADE_WEBSERVICE_USER" value="'.getDolGlobalString('AADE_WEBSERVICE_USER').'"';
+	print '</td><td></td></tr>';
+
+	print '<tr class="oddeven"><td>';
+	print '<span class="titlefield fieldrequired">'.$langs->trans("AADE_WEBSERVICE_KEY").'</span></td><td>';
+	print '<input class="minwidth300" type="text" name="AADE_WEBSERVICE_KEY" value="'.getDolGlobalString('AADE_WEBSERVICE_KEY').'"';
+	print '</td><td></td></tr>';
+
+	print '<br>';
+
+	print "</table>";
+}
+
 print $form->buttonsSaveCancel("Save", '');
 
 print '</form>';
diff --git a/htdocs/langs/en_US/companies.lang b/htdocs/langs/en_US/companies.lang
index 702a22ccc4d70..2b1b6038807dd 100644
--- a/htdocs/langs/en_US/companies.lang
+++ b/htdocs/langs/en_US/companies.lang
@@ -510,3 +510,4 @@ ShowSocialNetworks=Show social networks
 HideSocialNetworks=Hide social networks
 ExternalSystemID=External system ID
 IDOfPaymentInAnExternalSystem=ID of the payment mode into an external system (like Stripe, Paypal, ...)
+AADEWebserviceCredentials=AADE Webservice Credentials
diff --git a/htdocs/societe/card.php b/htdocs/societe/card.php
index b69448ff7fa8a..69960414e0b87 100644
--- a/htdocs/societe/card.php
+++ b/htdocs/societe/card.php
@@ -13,6 +13,8 @@
  * Copyright (C) 2018       Nicolas ZABOURI	        <info@inovea-conseil.com>
  * Copyright (C) 2018       Ferran Marcet		    <fmarcet@2byte.es.com>
  * Copyright (C) 2018-2022  Frédéric France         <frederic.france@netlogic.fr>
+ * Copyright (C) 2022-2023  George Gkantinas	    <info@geowv.eu>
+ * Copyright (C) 2023       Nick Fragoulis
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -63,6 +65,12 @@
 	require_once DOL_DOCUMENT_ROOT.'/eventorganization/class/conferenceorboothattendee.class.php';
 }
 
+if ($mysoc->country_code == 'GR') {
+	$u = getDolGlobalString('AADE_WEBSERVICE_USER');
+	$p = getDolGlobalString('AADE_WEBSERVICE_KEY');
+	$myafm = getDolGlobalString('MAIN_INFO_TVAINTRA');
+}
+
 
 // Load translation files required by the page
 
@@ -385,13 +393,13 @@
 	}
 
 	if ($action == 'set_localtax1') {
-		//obtidre selected del combobox
+		//get selected from combobox
 		$value = GETPOST('lt1');
 		$object->fetch($socid);
 		$res = $object->setValueFrom('localtax1_value', $value, '', null, 'text', '', $user, 'COMPANY_MODIFY');
 	}
 	if ($action == 'set_localtax2') {
-		//obtidre selected del combobox
+		//get selected from combobox
 		$value = GETPOST('lt2');
 		$object->fetch($socid);
 		$res = $object->setValueFrom('localtax2_value', $value, '', null, 'text', '', $user, 'COMPANY_MODIFY');
@@ -895,7 +903,7 @@
 							break;
 					}
 				}
-				// Gestion du logo de la société
+				// Company logo management
 
 
 				// Update linked member
@@ -1187,7 +1195,7 @@
 
 		$object->logo = (isset($_FILES['photo']) ?dol_sanitizeFileName($_FILES['photo']['name']) : '');
 
-		// Gestion du logo de la société
+		// Company logo management
 		$dir     = $conf->societe->multidir_output[$conf->entity]."/".$object->id."/logos";
 		$file_OK = (isset($_FILES['photo']) ?is_uploaded_file($_FILES['photo']['tmp_name']) : false);
 		if ($file_OK) {
@@ -1728,7 +1736,11 @@ function formatCustomerSelection (selection) {
 				print "\n";
 				print '<script type="text/javascript">';
 				print "function CheckVAT(a) {\n";
-				print "newpopup('".DOL_URL_ROOT."/societe/checkvat/checkVatPopup.php?vatNumber='+a, '".dol_escape_js($langs->trans("VATIntraCheckableOnEUSite"))."', ".$widthpopup.", ".$heightpopup.");\n";
+				if ($mysoc->country_code == 'GR' && $object->country_code == 'GR' && !empty($u)) {
+					print "GRVAT(a,'{$u}','{$p}','{$myafm}');\n";
+				} else {
+					print "newpopup('".DOL_URL_ROOT."/societe/checkvat/checkVatPopup.php?vatNumber='+a, '".dol_escape_js($langs->trans("VATIntraCheckableOnEUSite"))."', ".$widthpopup.", ".$heightpopup.");\n";
+				}
 				print "}\n";
 				print '</script>';
 				print "\n";
@@ -1957,7 +1969,7 @@ function formatCustomerSelection (selection) {
 				}
 			}
 			$modCodeClient = new $module($db);
-			// We verified if the tag prefix is used
+			// We check if the prefix tag is used
 			if ($modCodeClient->code_auto) {
 				$prefixCustomerIsUsed = $modCodeClient->verif_prefixIsUsed();
 			}
@@ -1973,7 +1985,7 @@ function formatCustomerSelection (selection) {
 				}
 			}
 			$modCodeFournisseur = new $module($db);
-			// On verifie si la balise prefix est utilisee
+			// We check if the prefix tag is used
 			if ($modCodeFournisseur->code_auto) {
 				$prefixSupplierIsUsed = $modCodeFournisseur->verif_prefixIsUsed();
 			}
@@ -2500,7 +2512,11 @@ function init_check_no_email(input) {
 					print "\n";
 					print '<script type="text/javascript">';
 					print "function CheckVAT(a) {\n";
-					print "newpopup('".DOL_URL_ROOT."/societe/checkvat/checkVatPopup.php?vatNumber='+a,'".dol_escape_js($langs->trans("VATIntraCheckableOnEUSite"))."', ".$widthpopup.", ".$heightpopup.");\n";
+					if ($mysoc->country_code == 'GR' && $object->country_code == 'GR' && !empty($u)) {
+						print "GRVAT(a,'{$u}','{$p}','{$myafm}');\n";
+					} else {
+						print "newpopup('".DOL_URL_ROOT."/societe/checkvat/checkVatPopup.php?vatNumber='+a, '".dol_escape_js($langs->trans("VATIntraCheckableOnEUSite"))."', ".$widthpopup.", ".$heightpopup.");\n";
+					}
 					print "}\n";
 					print '</script>';
 					print "\n";
@@ -2968,7 +2984,11 @@ function init_check_no_email(input) {
 					print "\n";
 					print '<script type="text/javascript">';
 					print "function CheckVAT(a) {\n";
-					print "newpopup('".DOL_URL_ROOT."/societe/checkvat/checkVatPopup.php?vatNumber='+a, '".dol_escape_js($langs->trans("VATIntraCheckableOnEUSite"))."', ".$widthpopup.", ".$heightpopup.");\n";
+					if ($mysoc->country_code == 'GR' && $object->country_code == 'GR' && !empty($u)) {
+						print "GRVAT(a,'{$u}','{$p}','{$myafm}');\n";
+					} else {
+						print "newpopup('".DOL_URL_ROOT."/societe/checkvat/checkVatPopup.php?vatNumber='+a, '".dol_escape_js($langs->trans("VATIntraCheckableOnEUSite"))."', ".$widthpopup.", ".$heightpopup.");\n";
+					}
 					print "}\n";
 					print '</script>';
 					print "\n";
@@ -3339,3 +3359,46 @@ function init_check_no_email(input) {
 // End of page
 llxFooter();
 $db->close();
+
+?>
+
+<script>
+// Function to retrieve VAT details from the Greek Ministry of Finance GSIS SOAP web service
+function GRVAT(a, u, p, myafm) {
+  var afm = a.replace(/\D/g, ""); // Remove non-digit characters from 'a'
+
+  $.ajax({
+	type: "GET",
+	url: "/societe/checkvat/checkVatGr.php",
+	data: { afm }, // Set request parameters
+	success: function(data) {
+		var obj = data; // Parse response data as JSON
+
+		// Update form fields based on retrieved data
+		if (obj.RgWsPublicBasicRt_out.afm === null) {
+			alert(obj.pErrorRec_out.errorDescr); // Display error message if AFM is null
+		} else {
+			$("#name").val(obj.RgWsPublicBasicRt_out.onomasia); // Set 'name' field value
+			$("#zipcode").val(obj.RgWsPublicBasicRt_out.postalZipCode); // Set 'zipcode' field value
+			$("#town").val(obj.RgWsPublicBasicRt_out.postalAreaDescription); // Set 'town' field value
+			$("#idprof2").val(obj.RgWsPublicBasicRt_out.doyDescr); // Set 'idprof2' field value
+			$("#name_alias_input").val(obj.RgWsPublicBasicRt_out.commerTitle); // Set 'name_alias' field value
+
+		if (obj.arrayOfRgWsPublicFirmActRt_out.RgWsPublicFirmActRtUser) {
+			var firmActUser = obj.arrayOfRgWsPublicFirmActRt_out.RgWsPublicFirmActRtUser;
+			
+		if (Array.isArray(firmActUser)) {
+			var primaryFirmAct = firmActUser.find(item => item.firmActKindDescr === "ΚΥΡΙΑ"); // Find primary client activity
+			if (primaryFirmAct) {
+				$("#idprof1").val(primaryFirmAct.firmActDescr); // Set 'idprof1' field value
+			}
+		} else {
+			$("#idprof1").val(firmActUser.firmActDescr); // Set 'idprof1' field value
+			}
+		}
+		}
+	}
+	});
+}
+
+</script>
diff --git a/htdocs/societe/checkvat/checkVatGr.php b/htdocs/societe/checkvat/checkVatGr.php
new file mode 100644
index 0000000000000..82684ac77815a
--- /dev/null
+++ b/htdocs/societe/checkvat/checkVatGr.php
@@ -0,0 +1,64 @@
+<?php
+/* Copyright (C) 2016       Spiros Ioannou
+ * Copyright (C) 2017       Marios Kaintatzis
+ * Copyright (C) 2023       Nick Fragoulis
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ *  \file       htdocs/societe/checkvat/checkVatGr.php
+ *  \ingroup    societe
+ *  \brief      Request VAT details from the Greek Ministry of Finance GSIS SOAP web service
+ */
+
+require "../../main.inc.php";
+
+$username = getDolGlobalString('AADE_WEBSERVICE_USER'); // Get username from request
+$password = getDolGlobalString('AADE_WEBSERVICE_KEY'); // Get password from request
+$myafm = getDolGlobalString('MAIN_INFO_TVAINTRA'); // Get Vat from request
+$afm = GETPOST('afm'); // Get client Vat from request
+
+// Make call to check VAT for Greek client
+$result = checkVATGR($username, $password, $myafm, $afm);
+
+top_httphead('application/json');
+echo json_encode($result); // Encode the result as JSON and output
+
+/**
+* Request VAT details
+* @param 	string 	$username 			Company AADE username
+* @param 	string 	$password 			Company AADE password
+* @param 	string 	$AFMcalledfor 		Company vat number
+* @param 	string 	$AFMcalledby 		Client vat number
+* @return   string
+*/
+function checkVATGR($username, $password, $AFMcalledfor, $AFMcalledby = '')
+{
+	$client = new SoapClient("https://www1.gsis.gr/webtax2/wsgsis/RgWsPublic/RgWsPublicPort?WSDL", array('trace' => true));
+	$authHeader = new stdClass();
+	$authHeader->UsernameToken = new stdClass();
+	$authHeader->UsernameToken->Username = "$username";
+	$authHeader->UsernameToken->Password = "$password";
+	$Headers[] = new SoapHeader('http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd', 'Security', $authHeader, true);
+	$client->__setSoapHeaders($Headers);
+	$result = $client->rgWsPublicAfmMethod(
+		array(
+			'afmCalledBy' => "$AFMcalledby",
+			'afmCalledFor' => "$AFMcalledfor",
+		)
+	);
+
+	return $result;
+}