There is no precise reply to this simple question. It depends. The closer you are to a tax deadline, the longer it can take, since usually accountants are busier this time of the year.
The whole process cannot last less than a month since a bank confirmation is required in order to perform the audit. Usually, banks requires 4 weeks in ordre to send this document to your accountant.
You should give your documentation to your accountant or auditor, at the minimum, 6 to 8 before Profit Tax Return filling deadline.
If you are not sure about your PTR deadline, we are available to clarify this information and schedule an accountant according to your needs.