diff --git a/htdocs/comm/propal/card.php b/htdocs/comm/propal/card.php
index e14a2c05246..6589587a8f6 100644
--- a/htdocs/comm/propal/card.php
+++ b/htdocs/comm/propal/card.php
@@ -923,6 +923,8 @@ if (empty($reshook)) {
 		$price_ttc = '';
 		$price_ttc_devise = '';
 
+		// TODO Implement  if (getDolGlobalInt('MAIN_UNIT_PRICE_WITH_TAX_IS_FOR_ALL_TAXES'))
+
 		if (GETPOST('price_ht') !== '') {
 			$price_ht = price2num(GETPOST('price_ht'), 'MU', 2);
 		}
diff --git a/htdocs/comm/propal/class/propal.class.php b/htdocs/comm/propal/class/propal.class.php
index 8606b9df87d..4bfe37810ed 100644
--- a/htdocs/comm/propal/class/propal.class.php
+++ b/htdocs/comm/propal/class/propal.class.php
@@ -865,6 +865,8 @@ class Propal extends CommonObject
 				$txtva = preg_replace('/\s*\(.*\)/', '', $txtva); // Remove code into vatrate.
 			}
 
+			// TODO Implement  if (getDolGlobalInt('MAIN_UNIT_PRICE_WITH_TAX_IS_FOR_ALL_TAXES')) ?
+
 			$tabprice = calcul_price_total($qty, $pu, $remise_percent, $txtva, $txlocaltax1, $txlocaltax2, 0, $price_base_type, $info_bits, $type, $mysoc, $localtaxes_type, 100, $this->multicurrency_tx, $pu_ht_devise);
 			$total_ht  = $tabprice[0];
 			$total_tva = $tabprice[1];
diff --git a/htdocs/core/tpl/objectline_edit.tpl.php b/htdocs/core/tpl/objectline_edit.tpl.php
index b2914c455a0..605634dab67 100644
--- a/htdocs/core/tpl/objectline_edit.tpl.php
+++ b/htdocs/core/tpl/objectline_edit.tpl.php
@@ -225,7 +225,11 @@ $coldisplay++;
 
 	if (!empty($inputalsopricewithtax) && !getDolGlobalInt('MAIN_NO_INPUT_PRICE_WITH_TAX')) {
 		$coldisplay++;
-		print '<td class="right"><input type="text" class="flat right" size="5" id="price_ttc" name="price_ttc" value="'.(GETPOSTISSET('price_ttc') ? GETPOST('price_ttc') : (isset($line->pu_ttc) ? price($line->pu_ttc, 0, '', 0) : '')).'"';
+		$upinctax = isset($line->pu_ttc) ? $line->pu_ttc : null;
+		if (getDolGlobalInt('MAIN_UNIT_PRICE_WITH_TAX_IS_FOR_ALL_TAXES')) {
+			$upinctax = price2num($line->total_ttc / $line->qty, 'MU');
+		}
+		print '<td class="right"><input type="text" class="flat right" size="5" id="price_ttc" name="price_ttc" value="'.(GETPOSTISSET('price_ttc') ? GETPOST('price_ttc') : (isset($upinctax) ? price($upinctax, 0, '', 0) : '')).'"';
 		if ($line->fk_prev_id != null) {
 			print ' readonly';
 		}
diff --git a/htdocs/core/tpl/objectline_view.tpl.php b/htdocs/core/tpl/objectline_view.tpl.php
index b2213862d62..153773a6519 100644
--- a/htdocs/core/tpl/objectline_view.tpl.php
+++ b/htdocs/core/tpl/objectline_view.tpl.php
@@ -326,7 +326,13 @@ print $tooltiponpriceend;
 <?php }
 
 if (!empty($inputalsopricewithtax) && !getDolGlobalInt('MAIN_NO_INPUT_PRICE_WITH_TAX')) { ?>
-	<td class="linecoluttc nowraponall right"><?php $coldisplay++; ?><?php print (isset($line->pu_ttc) ? price($sign * $line->pu_ttc) : price($sign * $line->subprice)); ?></td>
+	<td class="linecoluttc nowraponall right"><?php $coldisplay++; ?><?php
+	$upinctax = isset($line->pu_ttc) ? $line->pu_ttc : null;
+	if (getDolGlobalInt('MAIN_UNIT_PRICE_WITH_TAX_IS_FOR_ALL_TAXES')) {
+		$upinctax = price2num($line->total_ttc / $line->qty, 'MU');
+	}
+	print (isset($upinctax) ? price($sign * $upinctax) : price($sign * $line->subprice));
+	?></td>
 <?php } ?>
 
 	<td class="linecolqty nowraponall right"><?php $coldisplay++; ?>
diff --git a/htdocs/master.inc.php b/htdocs/master.inc.php
index 03515c9a2e2..69ce82e5657 100644
--- a/htdocs/master.inc.php
+++ b/htdocs/master.inc.php
@@ -218,6 +218,12 @@ if (!defined('NOREQUIREDB') && !defined('NOREQUIRESOC')) {
 		// For FR, default value of option to show profid SIRET is on by default
 		$conf->global->MAIN_PROFID1_IN_ADDRESS = 1;
 	}
+
+	if ($mysoc->localtax1_assuj || $mysoc->localtax2_assuj) {
+		// For countries using the 2nd or 3rd tax, we disable input/edit of lines using the price including tax (because 2nb and 3rd tax not yet taken into account).
+		// Work In Progress to support all taxes into unit price entry when MAIN_UNIT_PRICE_WITH_TAX_IS_FOR_ALL_TAXES is set.
+		$conf->global->MAIN_NO_INPUT_PRICE_WITH_TAX = 1;
+	}
 }