Hello Rui,

I once had this question for one of my clients and found the statement here: ‘It is not possible to change the tax localisation of a company once a journal entry has been posted.’ (see https://www.odoo.com/documentation/18.0/applications/finance/accounting/get_started/chart_of_accounts.html?msockid=1e563114daaf66740564243ddb636701)

I also created a support ticket with Odoo and received the following response:

‘I understand your concern and would like to inform you that there is no way to change the tax localisation once the entries have been posted. However, to install a different tax localisation, you may need to create a new company if you have a custom plan. You cannot change the tax localisation in the existing database or company. If you want to continue to apply the localisation to the same database, you may need to manually delete all posting records.’

However, deleting records that have already been posted is probably out of the question for security reasons - at least not if the customer is actively working with the system and it is not just a test system.

So in conclusion, I would say that this is not possible without pain.

The creation of a multi-company still sounds the most logical, but even that is likely to lead to ambiguities again and again in later processes.

Kind regards,
Chris Dominiak (Intero Technologies GmbH)