diff --git a/account_bank_statement_import_online_paypal/models/online_bank_statement_provider_paypal.py b/account_bank_statement_import_online_paypal/models/online_bank_statement_provider_paypal.py
index a0d54482..e64ff0c3 100644
--- a/account_bank_statement_import_online_paypal/models/online_bank_statement_provider_paypal.py
+++ b/account_bank_statement_import_online_paypal/models/online_bank_statement_provider_paypal.py
@@ -223,6 +223,9 @@ class OnlineBankStatementProviderPayPal(models.Model):
                 map(lambda x: self._paypal_transaction_to_lines(x), transactions)
             )
         )
+        # Make sure there are no duplicate unique_import_id's within a download.
+        # This way we still guard against importing twice the same data.
+        self._paypal_ensure_unique_import_ids(lines)
 
         first_transaction = transactions[0]
         first_transaction_id = first_transaction["transaction_info"]["transaction_id"]
@@ -319,6 +322,17 @@ class OnlineBankStatementProviderPayPal(models.Model):
             ]
         return lines
 
+    def _paypal_ensure_unique_import_ids(self, lines):
+        """Check id's are unique within a list of lines."""
+        check_ids = {}
+        for line in lines:
+            unique_import_id = line["unique_import_id"]
+            counter = 0
+            if unique_import_id in check_ids:
+                counter = check_ids[unique_import_id] + 1
+                line["unique_import_id"] = "%s-%d" % (unique_import_id, counter)
+            check_ids[unique_import_id] = counter
+
     def _paypal_get_token(self):
         self.ensure_one()
         data = self._paypal_retrieve(
diff --git a/account_bank_statement_import_online_paypal/tests/test_account_bank_statement_import_online_paypal.py b/account_bank_statement_import_online_paypal/tests/test_account_bank_statement_import_online_paypal.py
index 5adf7f48..a0ea5da3 100644
--- a/account_bank_statement_import_online_paypal/tests/test_account_bank_statement_import_online_paypal.py
+++ b/account_bank_statement_import_online_paypal/tests/test_account_bank_statement_import_online_paypal.py
@@ -805,3 +805,16 @@ class TestAccountBankAccountStatementImportOnlinePayPal(common.TransactionCase):
                 "unique_import_id": "1234567890-%s" % (self.today_timestamp,),
             },
         )
+
+    def test_ensure_unique(self):
+        lines = [
+            {"unique_import_id": "A", "name": "0 A key"},
+            {"unique_import_id": "A", "name": "1 A key 1"},
+            {"unique_import_id": "B", "name": "2 B key"},
+            {"unique_import_id": "A", "name": "3 A key 2"},
+        ]
+        self.OnlineBankStatementProvider._paypal_ensure_unique_import_ids(lines)
+        self.assertEqual(lines[0]["unique_import_id"], "A")
+        self.assertEqual(lines[1]["unique_import_id"], "A-1")
+        self.assertEqual(lines[2]["unique_import_id"], "B")
+        self.assertEqual(lines[3]["unique_import_id"], "A-2")