diff --git a/lib/strategies/BillNumberStrategy.class.php b/lib/strategies/BillNumberStrategy.class.php
index 2cd37a7..68660e1 100644
--- a/lib/strategies/BillNumberStrategy.class.php
+++ b/lib/strategies/BillNumberStrategy.class.php
@@ -78,12 +78,16 @@ protected function generateDefault($bill)
 	{
 		$billCount = $bill->getDocumentService()->createQuery()
 			->add(Restrictions::ne('publicationstatus', 'DRAFT'))
-			->setProjection(Projections::rowCount("billCount"))
-			->findColumn("billCount");
+			->add(Restrictions::like('label', '_____', MatchMode::EXACT()))
+			->setProjection(Projections::max('label', 'max'))
+			->findColumn('max');
 		return str_pad(strval($billCount[0]+1), 5, '0', STR_PAD_LEFT);
 	}
 }
 
+/**
+ * /!\ This strategy is incompatible with immediate order numbering (same numbering format than orders).
+ */
 class order_BillNumberYearSequenceStrategy implements order_BillNumberStrategy
 {
 	/**
@@ -92,18 +96,21 @@ class order_BillNumberYearSequenceStrategy implements order_BillNumberStrategy
 	 */
 	public function generate($bill)
 	{
-		$year = ($bill->getCreationdate()) ? substr($bill->getCreationdate(), 0, 4) : date("Y");
-		$beginDate = date_Converter::convertDateToGMT($year.'-01-01 00:00:00');
-		$endDate = date_Converter::convertDateToGMT(($year+1).'-01-01 00:00:00');
-		
-		$billCount = $bill->getDocumentService()->createQuery()
-						->setProjection(Projections::rowCount("billCount"))
-						->add(Restrictions::ne('publicationstatus', 'DRAFT'))
-						->add(Restrictions::ne('id', $bill->getId()))
-						->add(Restrictions::ge('transactionDate', $beginDate))
-						->add(Restrictions::lt('transactionDate', $endDate))
-						->findColumn("billCount");
-		$newCount = strval($billCount[0]+1);
+		$row = $bill->getDocumentService()->createQuery()
+			->add(Restrictions::ne('publicationstatus', 'DRAFT'))
+			->add(Restrictions::ne('id', $bill->getId()))
+			->add(Restrictions::like('label', $year.'________', MatchMode::EXACT()))
+			->addOrder(Order::desc('label'))
+			->setProjection(Projections::property('label'))
+			->findUnique();
+		if (is_array($row))
+		{
+			$newCount = strval(intval(substr($row['label'], 4))+1);
+		}
+		else
+		{
+			$newCount = '1';
+		}
 		return $year . str_pad($newCount, 8, '0', STR_PAD_LEFT);
 	}
 }
diff --git a/persistentdocument/order.class.php b/persistentdocument/order.class.php
index 78b9aab..75af22c 100644
--- a/persistentdocument/order.class.php
+++ b/persistentdocument/order.class.php
@@ -80,7 +80,7 @@ public function setTaxZone($taxZone)
 	}	
 		
 	/**
-	 * @return Array<String, Array<String, String>>
+	 * @return array<string, array<string, string>>
 	 */
 	public function getTotalTaxInfoArray()
 	{
@@ -99,7 +99,7 @@ public function getTotalTaxInfoArray()
 	
 	/**
 	 * @param string $propertyName
-	 * @param Mixed $value serializable data.
+	 * @param mixed $value serializable data.
 	 */
 	public function setGlobalProperty($propertyName, $value)
 	{
@@ -108,7 +108,7 @@ public function setGlobalProperty($propertyName, $value)
 	
 	/**
 	 * @param string $propertyName
-	 * @return Mixed
+	 * @return mixed
 	 */
 	public function getGlobalProperty($propertyName)
 	{
@@ -301,7 +301,7 @@ public function setDiscountDataArray($discountDataArray)
 	{
 		$this->setGlobalProperty('__discount', $discountDataArray);
 	}
-		
+	
 	/**
 	 * @return boolean
 	 */
@@ -410,7 +410,7 @@ public function getTaxRates()
 		{
 			$result = array();
 		}
-		return $result;		
+		return $result;
 	}
 	
 	/**
@@ -442,7 +442,7 @@ public function setShippingDataArray($shippingArray)
 		}
 		
 		$this->setGlobalProperty('__shipping', $shippingArray);
-	}	
+	}
 	
 	/**
 	 * @param shipping_persistentdocument_mode $shippingMode
@@ -455,7 +455,7 @@ public function setShippingModeDocument($shippingMode)
 			$this->setOrderProperty('shippingModeLabel', $shippingMode->getLabel());
 			$this->setOrderProperty('shippingModeCode', $shippingMode->getCode());
 		}
-		else 
+		else
 		{
 			$this->setShippingModeId(null);
 			$this->setOrderProperty('shippingModeLabel', null);
@@ -511,7 +511,7 @@ public function getShippingModeLabel()
 				}
 			}
 		} 
-		return implode(', ', $result);		
+		return implode(', ', $result);
 	}
 	
 	/**
@@ -576,7 +576,7 @@ public function setBillingModeDocument($billingMode)
 		{
 			$this->setBillingModeId(null);
 			$this->setOrderProperty('paymentConnectorLabel', null);
-			$this->setOrderProperty('paymentConnectorCode', null);			
+			$this->setOrderProperty('paymentConnectorCode', null);
 		}
 	}
 	
@@ -867,5 +867,5 @@ public function getModifierLineArray()
 	public function getTreeNodeLabel()
 	{
 		return $this->getOrderNumber();
-	}	
+	}
 }
\ No newline at end of file