A Tax Information Exchange Agreement (TIEA) provides for the exchange of information between 2 countries on request relating to a specific criminal or civil tax investigation.
Let’s assume that you set up a Tax Free Offshore Company in a country which has a TIEA with your home/taxing country.
How it works in practice is, if your home state becomes suspicious of your connection to or involvement with an Offshore Company (ie if they think an Offshore Company is being used by you to avoid domestic tax obligations), the Tax Authorities of your home country can request of the Tax Haven Country Government, as of right, (ie if there is a TIEA entered into between the 2 countries) that they give up the name and address of the “underlying beneficial owner” of the company in question.
Although the information isn’t publicly filed this information must/will be kept by the Tax Free Offshore Company’s local Registered Agent who is obliged by law (as a condition of its International Corporate Service Provider’s License) to hand over this information upon request by/to the local Financial Services Authority (who then pass ownership details to the Tax Haven’s Attorney General’s Office who then pass it down the line to the requesting country).
It goes without saying of course but if you want to minimize the chances of anyone ever discovering that you own a Tax Free Offshore Company ideally you will want to incorporate your Offshore Company in a jurisdiction which does NOT have a TIEA with your home/taxing state.