To avoid the requalification and potential issues for your customers, you need to have a solid freelance contract,
which is not the same as an employment contract. Therefore, if you don't have your own freelance services contract template, you better get one. Not every organisation is prepared to hire freelancers, and they may not have such documentation in place. You can find more about contracts here
Please note that the agreement you will put in place with your client should not specify the working hours or the subordination (i.e. you don't have a boss). You are also not expected to extensively report on what you do (as typically expected from employees), but only on what is related to the project.
You also should not seek approvals for your vacations and absence. You can inform your client about your time off, but they don't need to approve it. So ideally, don't put these requests in writing.
Make sure that you don't sign exclusivity agreements, as this may imply that you won't work with other organisations. The core principle of being a true freelancer (to avoid the reclassification) is that you work with more than one client
Have your own invoice template and payment conditions on it. You can find more about invoices here
You should be using your own equipment such as a phone and laptop. The company can provide you with equipment and resources, but it shouldn't oblige you to use them.
The compliance officer will check the organisation chart to see if you, as a freelancer, have an official status. While this procedure sounds very doubtful to us (we know lots of freelancers who are in leading roles in companies), it may still get the company in trouble.
As a freelancer, you should also not have evaluations or performance reviews as they do with staff. You of course are free to perform your own project performance reviews, if this is part of your work.