diff --git a/versions/18.0/pre_upgrade.sh b/versions/18.0/pre_upgrade.sh
index 05ae24c..2f63d87 100755
--- a/versions/18.0/pre_upgrade.sh
+++ b/versions/18.0/pre_upgrade.sh
@@ -131,6 +131,13 @@ EOF
 echo "SQL command = $PRE_MIGRATE_SQL"
 query_postgres_container "$PRE_MIGRATE_SQL" ou18 || exit 1
 
+# NOTE: Missing generic PCG account xml-ids expected by l10n_fr_account (e.g.
+# account.<company>_pcg_607_account / _pcg_707_account) are recreated generically
+# by the ORM post-migration script
+#   versions/18.0/scripts/l10n_fr_account/18.0.2.2/post-migration-0k-fix-property-account-xmlids.py
+# which runs at stage "post" of l10n_fr_account, before the native "end" script
+# end-migrate_update_taxes.py that would otherwise crash on the missing xml-id.
+
 # Copy filestores
 copy_filestore ou17 ou17 ou18 ou18 || exit 1
 
diff --git a/versions/18.0/scripts/l10n_fr_account/18.0.2.2/post-migration-0k-fix-property-account-xmlids.py b/versions/18.0/scripts/l10n_fr_account/18.0.2.2/post-migration-0k-fix-property-account-xmlids.py
new file mode 100644
index 0000000..296c9fa
--- /dev/null
+++ b/versions/18.0/scripts/l10n_fr_account/18.0.2.2/post-migration-0k-fix-property-account-xmlids.py
@@ -0,0 +1,195 @@
+# Copyright 0k / Élabore
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
+#
+# Custom OpenUpgrade migration script, injected through a dedicated
+# --upgrade-path (see versions/18.0/upgrade.sh). Runs at stage "post" of
+# l10n_fr_account/18.0.2.2, i.e. BEFORE the global "end" stage where the native
+# l10n_fr_account/migrations/2.1/end-migrate_update_taxes.py runs.
+#
+# Problem
+# -------
+# end-migrate_update_taxes.py calls account.chart.template.try_loading('fr', ...).
+# During _post_load_data(), Odoo 18 resolves the French template's default
+# accounts via self.ref() WITHOUT raise_if_not_found=False, at three places:
+#   - property_account_income_categ_id  (pcg_707_account) -> chart_template.py:711
+#   - property_account_expense_categ_id (pcg_607_account) -> chart_template.py:714
+#   - every _get_property_accounts()/additional_properties account -> :746
+# If any expected account xml-id "account.<company>_<key>" is missing, it raises:
+#   ValueError: External ID not found in the system: account.1_pcg_607_account
+# which aborts the whole registry load.
+#
+# This happens when a database customized its chart of accounts: the generic PCG
+# account was deleted (e.g. 607000) or recreated without its xml-id (e.g. 707000).
+#
+# Fix (generic, not hardcoded to 607/707)
+# ---------------------------------------
+# For every company with a chart_template, we read the list of account xml-ids
+# the template expects (dynamically, from the template ORM API), and for each one
+# that is missing in the DB we recreate the "account.<company>_<key>" ir.model.data
+# pointing to the best matching real account:
+#   1. the account whose code matches exactly the template account code,
+#   2. otherwise the company account whose code shares the longest common prefix
+#      with the template code (e.g. 607000 -> 607100),
+#   3. otherwise nothing (logged as a warning; never blocks).
+# No account is modified; only missing xml-ids are (re)created. Idempotent.
+import logging
+
+from openupgradelib import openupgrade
+
+_logger = logging.getLogger(__name__)
+
+
+def _collect_property_account_xmlids(template, code, accounts_csv):
+    """Return the set of template account xml-ids referenced as property accounts.
+
+    Sources:
+      - template._get_property_accounts({})  (receivable, payable, expense, income, ...)
+      - the template_data dict (property_account_*_id keys)
+      - additional_properties declared on res.company template data
+    Only keep values that are real account xml-ids of this template, i.e. present
+    in accounts_csv (this filters out journals and dotted external ids).
+    """
+    xmlids = set()
+
+    # 1. Base property accounts (model-level defaults)
+    try:
+        prop_fields = template._get_property_accounts({})
+    except Exception as exc:  # noqa: BLE001
+        _logger.warning("Could not read _get_property_accounts: %s", exc)
+        prop_fields = {}
+
+    # 2. Full template data: template_data holds property_account_*_id values,
+    #    res.company holds additional_properties (currency exchange, deferral...).
+    try:
+        tdata = template._get_chart_template_data(code)
+    except Exception as exc:  # noqa: BLE001
+        _logger.warning("Could not read _get_chart_template_data(%s): %s", code, exc)
+        tdata = {}
+
+    candidate_values = []
+
+    template_data = tdata.get("template_data", {}) if tdata else {}
+    for key, value in template_data.items():
+        if key in prop_fields or key.startswith("property_"):
+            candidate_values.append(value)
+
+    # additional_properties live inside the res.company template values
+    res_company = tdata.get("res.company", {}) if tdata else {}
+    for _company_key, company_vals in res_company.items():
+        if not isinstance(company_vals, dict):
+            continue
+        add_props = company_vals.get("additional_properties")
+        if isinstance(add_props, dict):
+            candidate_values.extend(add_props.values())
+
+    # Keep only plain (non-dotted) xml-ids that are actual accounts of the template
+    for value in candidate_values:
+        if isinstance(value, str) and value and "." not in value and value in accounts_csv:
+            xmlids.add(value)
+
+    return xmlids
+
+
+def _find_best_account(env, company, target_code):
+    """Return the best account record for a template account code, or None.
+
+    1. exact code match for the company;
+    2. otherwise the company account whose code shares the longest common prefix
+       with target_code; ties are broken by smallest code (deterministic).
+    3. otherwise None.
+
+    The exact fallback account matters little functionally: it is only used as a
+    journal's default_account_id / an ir.default, which stays user-overridable.
+    The goal is to provide a valid account of the right family so that
+    try_loading() no longer crashes on a missing external id.
+    """
+    if not target_code:
+        return None
+
+    Account = env["account.account"]
+    company_domain = [("company_ids", "in", company.id)]
+
+    exact = Account.search(company_domain + [("code", "=", target_code)], limit=1)
+    if exact:
+        return exact
+
+    # Longest common prefix fallback; ties broken by smallest code.
+    candidates = Account.search(company_domain)
+    best = None
+    best_key = None  # (prefix_len, negated-code-for-min) -> maximize
+    for acc in candidates:
+        code = acc.code or ""
+        common = 0
+        for a, b in zip(code, target_code):
+            if a != b:
+                break
+            common += 1
+        if common == 0:
+            continue
+        key = (common, tuple(-ord(c) for c in code))  # longer prefix, then smallest code
+        if best_key is None or key > best_key:
+            best = acc
+            best_key = key
+    return best
+
+
+@openupgrade.migrate()
+def migrate(env, version):
+    template = env["account.chart.template"]
+    companies = env["res.company"].search([("chart_template", "!=", False)])
+
+    created = 0
+    for company in companies:
+        code = company.chart_template
+        tmpl = template.with_company(company)
+
+        try:
+            accounts_csv = tmpl._get_account_account(code)
+        except Exception as exc:  # noqa: BLE001
+            _logger.warning(
+                "Company %s (%s): cannot read template accounts: %s",
+                company.id, code, exc,
+            )
+            continue
+
+        expected = _collect_property_account_xmlids(tmpl, code, accounts_csv)
+
+        for tmpl_xmlid in sorted(expected):
+            full = f"account.{company.id}_{tmpl_xmlid}"
+            if env.ref(full, raise_if_not_found=False):
+                continue
+            if company.parent_ids:
+                parent_full = (
+                    f"account.{company.parent_ids[0].id}_{tmpl_xmlid}"
+                )
+                if env.ref(parent_full, raise_if_not_found=False):
+                    continue
+
+            target_code = accounts_csv.get(tmpl_xmlid, {}).get("code")
+            account = _find_best_account(env, company, target_code)
+            if not account:
+                _logger.warning(
+                    "Company %s: no account found for template xml-id %s "
+                    "(code %s); skipping",
+                    company.id, tmpl_xmlid, target_code,
+                )
+                continue
+
+            env["ir.model.data"].create({
+                "module": "account",
+                "name": f"{company.id}_{tmpl_xmlid}",
+                "model": "account.account",
+                "res_id": account.id,
+                "noupdate": True,
+            })
+            created += 1
+            _logger.info(
+                "Company %s: created xml-id %s -> account %s (%s) for "
+                "template code %s",
+                company.id, full, account.id, account.code, target_code,
+            )
+
+    _logger.info(
+        "[l10n_fr_account] property-account xml-id fix: %s xml-id(s) created",
+        created,
+    )