diff --git a/htdocs/compta/facture/card.php b/htdocs/compta/facture/card.php
index b97d22631a1..a134afba603 100644
--- a/htdocs/compta/facture/card.php
+++ b/htdocs/compta/facture/card.php
@@ -990,6 +990,11 @@ if (empty($reshook))
 				}
 				$id = $object->create($user);
 
+				// NOTE: Pb with situation invoice
+				// NOTE: fields total on situation invoice are stored as cumulative values on total of lines (bad) but delta on invoice total
+				// NOTE: fields total on credit note are stored as delta both on total of lines and on invoice total (good)
+				// NOTE: fields situation_percent on situation invoice are stored as cumulative values on lines (bad)
+				// NOTE: fields situation_percent on credit note are stored as delta on lines (good)
 				if (GETPOST('invoiceAvoirWithLines', 'int')==1 && $id>0)
 				{
 					if (!empty($facture_source->lines))
@@ -1010,36 +1015,38 @@ if (empty($reshook))
 							}
 
 
-
-
-							if($facture_source->type == Facture::TYPE_SITUATION)
+							if ($facture_source->type == Facture::TYPE_SITUATION)
 							{
 							    $source_fk_prev_id = $line->fk_prev_id; // temporary storing situation invoice fk_prev_id
-							    $line->fk_prev_id  = $line->id; // Credit note line need to be linked to the situation invoice it is create from
+							    $line->fk_prev_id  = $line->id; // The new line of the new credit note we are creating must be linked to the situation invoice line it is created from
 
-							    if(!empty($facture_source->tab_previous_situation_invoice))
+							    if (!empty($facture_source->tab_previous_situation_invoice))
 							    {
-							        // search the last invoice in cycle
-							        $lineIndex = count($facture_source->tab_previous_situation_invoice) - 1;
+							        // search the last standard invoice in cycle and the possible credit note between this last and facture_source
+							    	// TODO Move this out of loop of $facture_source->lines
+							    	$tab_jumped_credit_notes = array();
+							    	$lineIndex = count($facture_source->tab_previous_situation_invoice) - 1;
 							        $searchPreviousInvoice = true;
-							        while( $searchPreviousInvoice )
+							        while ($searchPreviousInvoice)
 							        {
-							            if($facture_source->tab_previous_situation_invoice[$lineIndex]->type  == Facture::TYPE_SITUATION || $lineIndex < 1)
+							            if ($facture_source->tab_previous_situation_invoice[$lineIndex]->type  == Facture::TYPE_SITUATION || $lineIndex < 1)
 							            {
 							                $searchPreviousInvoice=false; // find, exit;
 							                break;
 							            }
 							            else
 							            {
+							            	if ($facture_source->tab_previous_situation_invoice[$lineIndex]->type  == Facture::TYPE_CREDIT_NOTE) {
+							            		$tab_jumped_credit_notes[$lineIndex] = $facture_source->tab_previous_situation_invoice[$lineIndex]->id;
+							            	}
 							                $lineIndex--; // go to previous invoice in cycle
 							            }
 							        }
 
-
 							        $maxPrevSituationPercent = 0;
-							        foreach($facture_source->tab_previous_situation_invoice[$lineIndex]->lines as $prevLine)
+							        foreach ($facture_source->tab_previous_situation_invoice[$lineIndex]->lines as $prevLine)
 							        {
-							            if($prevLine->id == $source_fk_prev_id)
+							            if ($prevLine->id == $source_fk_prev_id)
 							            {
 							                $maxPrevSituationPercent = max($maxPrevSituationPercent, $prevLine->situation_percent);
 
@@ -1059,6 +1066,36 @@ if (empty($reshook))
 
 							        // prorata
 							        $line->situation_percent = $maxPrevSituationPercent - $line->situation_percent;
+
+							        //print 'New line based on invoice id '.$facture_source->tab_previous_situation_invoice[$lineIndex]->id.' fk_prev_id='.$source_fk_prev_id.' will be fk_prev_id='.$line->fk_prev_id.' '.$line->total_ht.' '.$line->situation_percent.'<br>';
+
+							        // If there is some credit note between last situation invoice and invoice used for credit note generation (note: credit notes are stored as delta)
+							        $maxPrevSituationPercent = 0;
+							        foreach ($tab_jumped_credit_notes as $index => $creditnoteid) {
+							        	foreach ($facture_source->tab_previous_situation_invoice[$index]->lines as $prevLine)
+							        	{
+							        		if ($prevLine->fk_prev_id == $source_fk_prev_id)
+							        		{
+							        			$maxPrevSituationPercent = $prevLine->situation_percent;
+
+							        			$line->total_ht  -= $prevLine->total_ht;
+							        			$line->total_tva -= $prevLine->total_tva;
+							        			$line->total_ttc -= $prevLine->total_ttc;
+							        			$line->total_localtax1 -= $prevLine->total_localtax1;
+							        			$line->total_localtax2 -= $prevLine->total_localtax2;
+
+							        			$line->multicurrency_subprice  -= $prevLine->multicurrency_subprice;
+							        			$line->multicurrency_total_ht  -= $prevLine->multicurrency_total_ht;
+							        			$line->multicurrency_total_tva -= $prevLine->multicurrency_total_tva;
+							        			$line->multicurrency_total_ttc -= $prevLine->multicurrency_total_ttc;
+							        		}
+							        	}
+							        }
+
+							        // prorata
+							        $line->situation_percent += $maxPrevSituationPercent;
+
+							        //print 'New line based on invoice id '.$facture_source->tab_previous_situation_invoice[$lineIndex]->id.' fk_prev_id='.$source_fk_prev_id.' will be fk_prev_id='.$line->fk_prev_id.' '.$line->total_ht.' '.$line->situation_percent.'<br>';
 							    }
 							}
 
@@ -1078,7 +1115,7 @@ if (empty($reshook))
 							$line->multicurrency_total_tva = -$line->multicurrency_total_tva;
 							$line->multicurrency_total_ttc = -$line->multicurrency_total_ttc;
 
-							$result = $line->insert(0, 1);     // When creating credit note with same lines than source, we must ignore error if discount alreayd linked
+							$result = $line->insert(0, 1);     // When creating credit note with same lines than source, we must ignore error if discount already linked
 
 							$object->lines[] = $line; // insert new line in current object