Index: src/include/lib/Garradin/Accounting/Transactions.php
==================================================================
--- src/include/lib/Garradin/Accounting/Transactions.php
+++ src/include/lib/Garradin/Accounting/Transactions.php
@@ -219,17 +219,30 @@
 					throw new UserException(sprintf('le compte "%s" n\'existe pas dans le plan comptable', $row->account));
 				}
 
 				$row->line_id = trim($row->line_id);
 				$id_analytical = null;
+				$data = [
+					'credit'     => $row->credit ?: 0,
+					'debit'      => $row->debit ?: 0,
+					'id_account' => $id_account,
+					'reference'  => $row->line_reference,
+					'label'      => $row->line_label,
+					'reconciled' => $row->reconciled,
+				];
 
 				if (!empty($row->analytical)) {
 					$id_analytical = $accounts->getIdFromCode($row->analytical);
 
 					if (!$id_analytical) {
 						throw new UserException(sprintf('le compte analytique "%s" n\'existe pas dans le plan comptable', $row->analytical));
 					}
+
+					$row['id_analytical'] = $id_analytical;
+				}
+				elseif (property_exists($row, 'analytical')) {
+					$row['id_analytical'] = null;
 				}
 
 				if ($row->line_id) {
 					$line = $transaction->getLine((int)$row->line_id);
 
@@ -239,19 +252,11 @@
 				}
 				else {
 					$line = new Line;
 				}
 
-				$line->importForm([
-					'credit'     => $row->credit ?: 0,
-					'debit'      => $row->debit ?: 0,
-					'id_account' => $id_account,
-					'reference'  => $row->line_reference,
-					'label'      => $row->line_label,
-					'reconciled' => $row->reconciled,
-					'id_analytical' => $id_analytical,
-				]);
+				$line->importForm($data);
 
 				if (!$row->line_id) {
 					$transaction->addLine($line);
 				}
 			}

Index: src/include/lib/Garradin/Entities/Accounting/Line.php
==================================================================
--- src/include/lib/Garradin/Entities/Accounting/Line.php
+++ src/include/lib/Garradin/Entities/Accounting/Line.php
@@ -54,27 +54,14 @@
 		$value = parent::filterUserValue($type, $value, $key);
 
 		return $value;
 	}
 
-	public function importForm(array $source = null)
-	{
-		if (null === $source) {
-			$source = $_POST;
-		}
-
-		if (empty($source['id_analytical'])) {
-			unset($source['id_analytical']);
-		}
-
-		return parent::importForm($source);
-	}
-
 	public function selfCheck(): void
 	{
 		parent::selfCheck();
 		$this->assert($this->credit || $this->debit, 'Aucun montant au débit ou au crédit');
 		$this->assert(($this->credit * $this->debit) === 0 && ($this->credit + $this->debit) > 0, 'Ligne non équilibrée : crédit ou débit doit valoir zéro.');
 		$this->assert($this->id_transaction, 'Aucun mouvement n\'a été indiqué pour cette ligne.');
 		$this->assert($this->reconciled === 0 || $this->reconciled === 1);
 	}
 }