diff --git a/account_payment_term_extension/models/account_payment_term.py b/account_payment_term_extension/models/account_payment_term.py
index 4dd72cc1ca0..2d73fb3c774 100644
--- a/account_payment_term_extension/models/account_payment_term.py
+++ b/account_payment_term_extension/models/account_payment_term.py
@@ -183,12 +183,13 @@ def _compute_terms(
                 term_vals["company_amount"] = company_line_amount
                 term_vals["foreign_amount"] = line_amount
             else:
-                # Percentage amounts
+                # Percentage amounts - use remaining_amount for correct calculation
+                # when there are fixed amounts on previous lines
                 line_amount = line.compute_line_amount(
-                    total_amount, remaining_amount, precision_digits
+                    remaining_amount, remaining_amount, precision_digits
                 )
                 company_line_amount = line.compute_line_amount(
-                    total_amount_currency,
+                    remaining_amount_currency,
                     remaining_amount_currency,
                     company_precision_digits,
                 )
diff --git a/account_payment_term_extension/models/account_payment_term_line.py b/account_payment_term_extension/models/account_payment_term_line.py
index b1751250e45..590544fa5c6 100644
--- a/account_payment_term_extension/models/account_payment_term_line.py
+++ b/account_payment_term_extension/models/account_payment_term_line.py
@@ -150,7 +150,8 @@ def compute_line_amount(self, total_amount, remaining_amount, precision_digits):
         if self.value == "fixed":
             return float_round(self.value_amount, precision_digits=precision_digits)
         elif self.value in ("percent", "percent_amount_untaxed"):
-            amt = total_amount * self.value_amount / 100.0
+            # Use remaining_amount to correctly handle fixed amounts on previous lines
+            amt = remaining_amount * self.value_amount / 100.0
             if self.amount_round:
                 amt = float_round(amt, precision_rounding=self.amount_round)
             return float_round(amt, precision_digits=precision_digits)