Hi,

The reporting engine in v18 builds dynamic groups and hierarchies based on account codes. Allowing special characters (like -) breaks the parser for ranges, intervals, and hierarchical structures. That’s why Odoo made this stricter — it simplifies grouping and avoids bugs in financial reports.

1-Recommended approach (adapt codes):

Replace hyphens with dots or numbers. For example:

    1000-01 → 1000.01

    2100-22 → 2100.22

2- If your client insists on using hyphens, you can override the constraint in a custom addon. Example:

from odoo import api, models

class AccountAccount(models.Model):

    _inherit = "account.account"

    @api.constrains('code')

    def _check_account_code(self):

        # Override: allow hyphens too

        for account in self:

            if not re.match(r'^[A-Za-z0-9.-]+$', account.code):

                raise ValidationError(

                    "The account code can only contain alphanumeric characters, dots and hyphens."

                )

Downside: You’ll have to patch the reporting engine as well, because the default grouping logic may not handle -. This means you might run into errors when printing general ledger, trial balance, or consolidated reports.

3- Keep the official account code in Odoo without the hyphen (e.g. 100001) but add a custom field for the “legacy code” with hyphens (for display/printing). This way you stay compliant with Odoo’s constraints, but users still see the familiar format on reports.

Hope it helps

The Odoo 18.0 constraint on account codes, preventing hyphens, is due to the new account report engine's requirements for alphanumeric characters and dots only. This ensures compatibility and avoids issues during report generation.

  Consider alternative account code structures that comply with Odoo's constraint. For example, use 100001, 210022, or similar.

  If you require hyphens for organizational reasons, explore custom development options to modify the validation rule. This would involve altering the _check_account_code method to accept hyphens, but it requires careful consideration of potential downstream effects on reporting.

  Thoroughly test any custom modifications in a development environment before deploying them to production to avoid data inconsistencies or report errors.

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