diff --git a/fusion_accounting_followup/__manifest__.py b/fusion_accounting_followup/__manifest__.py
index 0ffeb741..16f9c8e7 100644
--- a/fusion_accounting_followup/__manifest__.py
+++ b/fusion_accounting_followup/__manifest__.py
@@ -1,6 +1,6 @@
 {
     'name': 'Fusion Accounting Follow-up',
-    'version': '19.0.1.0.9',
+    'version': '19.0.1.0.10',
     'category': 'Accounting/Accounting',
     'summary': 'AI-augmented customer follow-ups (dunning) for unpaid invoices.',
     'description': """
diff --git a/fusion_accounting_followup/models/__init__.py b/fusion_accounting_followup/models/__init__.py
index 76c956a5..4a181971 100644
--- a/fusion_accounting_followup/models/__init__.py
+++ b/fusion_accounting_followup/models/__init__.py
@@ -2,3 +2,4 @@ from . import fusion_followup_level
 from . import fusion_followup_run
 from . import fusion_followup_text_cache
 from . import res_partner
+from . import account_move_line
diff --git a/fusion_accounting_followup/models/account_move_line.py b/fusion_accounting_followup/models/account_move_line.py
new file mode 100644
index 00000000..369ce57a
--- /dev/null
+++ b/fusion_accounting_followup/models/account_move_line.py
@@ -0,0 +1,14 @@
+"""Inherit account.move.line: track last follow-up level."""
+
+from odoo import _, api, fields, models
+
+
+class AccountMoveLine(models.Model):
+    _inherit = "account.move.line"
+
+    fusion_followup_level_id = fields.Many2one(
+        'fusion.followup.level', copy=False,
+        help="Last follow-up level at which this line was contacted.")
+    fusion_followup_last_run_date = fields.Datetime(
+        copy=False,
+        help="When the line was most-recently included in a follow-up.")
diff --git a/fusion_accounting_followup/tests/__init__.py b/fusion_accounting_followup/tests/__init__.py
index 803fa97a..4222b80d 100644
--- a/fusion_accounting_followup/tests/__init__.py
+++ b/fusion_accounting_followup/tests/__init__.py
@@ -7,3 +7,4 @@ from . import test_fusion_followup_level
 from . import test_fusion_followup_run
 from . import test_fusion_followup_text_cache
 from . import test_res_partner_inherit
+from . import test_account_move_line_inherit
diff --git a/fusion_accounting_followup/tests/test_account_move_line_inherit.py b/fusion_accounting_followup/tests/test_account_move_line_inherit.py
new file mode 100644
index 00000000..9860dd27
--- /dev/null
+++ b/fusion_accounting_followup/tests/test_account_move_line_inherit.py
@@ -0,0 +1,34 @@
+from odoo import fields as odoo_fields
+from odoo.tests.common import TransactionCase
+from odoo.tests import tagged
+
+
+@tagged('post_install', '-at_install')
+class TestAccountMoveLineFollowup(TransactionCase):
+    """Verify follow-up tracking fields are added to account.move.line."""
+
+    def test_fields_exist_on_model(self):
+        """Both new fields are declared on account.move.line."""
+        AML = self.env['account.move.line']
+        self.assertIn('fusion_followup_level_id', AML._fields)
+        self.assertIn('fusion_followup_last_run_date', AML._fields)
+        self.assertEqual(
+            AML._fields['fusion_followup_level_id'].comodel_name,
+            'fusion.followup.level',
+        )
+
+    def test_assign_level_and_date_on_existing_line(self):
+        """We can write the new fields onto an existing move line."""
+        line = self.env['account.move.line'].search([], limit=1)
+        if not line:
+            self.skipTest("No account.move.line records present in DB to test against.")
+        level = self.env['fusion.followup.level'].create({
+            'name': 'Reminder', 'sequence': 601, 'delay_days': 7, 'tone': 'gentle',
+        })
+        when = odoo_fields.Datetime.now()
+        line.write({
+            'fusion_followup_level_id': level.id,
+            'fusion_followup_last_run_date': when,
+        })
+        self.assertEqual(line.fusion_followup_level_id, level)
+        self.assertEqual(line.fusion_followup_last_run_date, when)