diff --git a/include/class/tva_rate_mtable.class.php b/include/class/tva_rate_mtable.class.php
index bb4c40917..2252f9d45 100644
--- a/include/class/tva_rate_mtable.class.php
+++ b/include/class/tva_rate_mtable.class.php
@@ -204,7 +204,7 @@ class Tva_Rate_MTable extends Manage_Table_SQL
      */
     function save()
     {
-        if ( $this->previous_id == null ) {
+        if ( $this->previous_id === null ) {
             throw new \Exception ("TVA184: no previous TVA id");
         }
         $cn=Dossier::connect();
@@ -257,11 +257,11 @@ class Tva_Rate_MTable extends Manage_Table_SQL
     function check()
     {
         $cn=Dossier::connect();
-        if ( $this->previous_id == null ) {
+        if ( $this->previous_id === null ) {
             throw new \Exception ("TVA184: no previous TVA id");
         }
         // both accounting can not be empty
-        if (trim($this->table->tva_purchase)==""&&trim($this->table->tva_sale)=="")
+        if (trim($this->table->tva_purchase??"")==""&&trim($this->table->tva_sale??"")=="")
         {
             $this->set_error("tva_purchase",
                     _("Les 2 postes comptables ne peuvent être nuls"));
@@ -270,7 +270,7 @@ class Tva_Rate_MTable extends Manage_Table_SQL
         }
 
         // Check the tva rate
-        if (trim($this->table->tva_rate)==""||isNumber($this->table->tva_rate)==0||$this->table->tva_rate>1)
+        if (trim($this->table->tva_rate??"")==""||isNumber($this->table->tva_rate)==0||$this->table->tva_rate>1)
         {
             $this->set_error("tva_rate", _("Taux de TVA invalide"));
         }
@@ -284,7 +284,7 @@ class Tva_Rate_MTable extends Manage_Table_SQL
         }
 
         // Check accounting exists for purchase
-        if (trim($this->table->tva_purchase)!=""&&$this->table->tva_purchase!="#")
+        if (trim($this->table->tva_purchase??"")!=""&&$this->table->tva_purchase!="#")
         {
             $count=$cn->get_value("select count(*) from tmp_pcmn where pcm_val = $1",
                     [$this->table->tva_purchase]);
@@ -294,7 +294,7 @@ class Tva_Rate_MTable extends Manage_Table_SQL
             }
         }
         // Check accounting exists for sale
-        if (trim($this->table->tva_sale)!=""&&$this->table->tva_sale!="#")
+        if (trim($this->table->tva_sale??"")!=""&&$this->table->tva_sale!="#")
         {
             $count=$cn->get_value("select count(*) from tmp_pcmn where pcm_val = $1",
                     [$this->table->tva_sale]);
@@ -309,19 +309,27 @@ class Tva_Rate_MTable extends Manage_Table_SQL
         {
             $this->set_error("tva_both_side", _("Choix incorrect"));
         }
-        $flag = true;
-        if ( isNumber($this->table->tva_id) == 0 || $this->table->tva_id != round($this->table->tva_id) )
-        {
-            $this->set_error("tva_id",_("Valeur invalide"));
-            $flag=false;
-        }
+
         // Check if old tva_id was not overwritting something
-        if ( $flag && $this->previous_id != $this->table->tva_id && $cn->get_value("select count(*) from tva_rate where tva_id=$1",[$this->table->tva_id]) > 0)
+        if (  $this->previous_id != $this->table->tva_id && $cn->get_value("select count(*) from tva_rate where tva_id=$1",[$this->table->tva_id]) > 0)
         {
             $this->set_error("tva_id",_("Code TVA déjà utilisé"));
         }
-        // Check that tva_id is a integer not a float
+        // Check that tva code is unique and remove not letter
+        $this->table->tva_code=strtoupper(trim( $this->table->tva_code));
+        $tva_code=$this->table->tva_code;
 
+        $tva_code=strtoupper($tva_code);
+        $tva_code=preg_replace("/[A-Z]/", "", $tva_code);
+        $tva_code=preg_replace("/[0-9]/", "", $tva_code);
+
+        if (strlen($tva_code)>0){
+            $this->set_error("tva_code", _("code tva : Uniquement des chiffres et des lettres"));
+        }
+
+        if (strlen($this->table->tva_code)>5){
+            $this->set_error("tva_code", _("code tva : Maximum 5 caractères"));
+        }
         if ($this->count_error()!=0)
             return false;
         return true;
diff --git a/unit-test/include/class/Acc_TVATest.php b/unit-test/include/class/Acc_TVATest.php
index e42b07153..14aa91c7a 100644
--- a/unit-test/include/class/Acc_TVATest.php
+++ b/unit-test/include/class/Acc_TVATest.php
@@ -71,4 +71,51 @@ class Acc_TVATest extends TestCase
         $this->assertEquals(0.2100 , $tva->tva_rate,"Cannot get tva rate after set_parameter");
     }
 
+    /**
+     * @brief display error from tva_rate_mtable
+     * @param Tva_Rate_MTable $tva_rate_mtable
+     * @return void
+     */
+    function display_error(Tva_Rate_MTable $tva_rate_mtable) {
+        $col=$tva_rate_mtable->get_order();
+        foreach($col as $item) {
+            $error =  $tva_rate_mtable->get_error($item);
+            if ( !empty ($error)) print "$error \n";
+        }
+    }
+
+    function dataCheck()  {
+         return array(
+             ['abc',true]
+             ,['13A',true]
+             ,['1',true]
+             ,['1-A',false]
+             ,['+a',false]
+             ,['abcdefg',false]
+         );
+    }
+
+    /**
+     * @testDox check TVA_CODE value
+     * @dataProvider dataCheck
+     * @return void
+     */
+    function testCheck($tva_code,$result)
+    {
+        $cn=\Dossier::connect();
+        $vtva_rate=new V_Tva_rate_SQL($cn,-1);
+        $vtva_rate->tva_code=$tva_code;
+        $vtva_rate->tva_label="Test";
+        $vtva_rate->tva_sale="451";
+        $vtva_rate->tva_both_side="0";
+        $vtva_rate->tva_rate=0.21;
+
+        $tva_rate_mtable=new Tva_Rate_MTable($vtva_rate);
+        $tva_rate_mtable->setPreviousId(0);
+
+        $check = $tva_rate_mtable->check();
+        $this->assertTrue($result==$check," erreur pour $tva_code ");
+        $this->display_error($tva_rate_mtable);
+    }
+
 }
\ No newline at end of file