Unpaid taxes may well be the reason for not releasing you abroad. If you have accumulated a considerable amount of tax arrears, then no persuasions and promises to repay them immediately on the spot will not help you if the fact of the established restriction due to non-payment of taxes is found at the border. However, do not be unnecessarily frightened and believe that if you forgot to pay a transport tax of several thousand rubles, for example, you will not automatically be able to leave Russia abroad. To understand everything, be sure to read this article to the end.
In fact, restrictions on travel abroad can only be set by bailiffs, but not by the tax inspectorate, even if you have not paid something there. The mechanism for banning the restriction is somewhat more complicated:
So, first you must accumulate a certain amount of tax arrears to the tax inspectorate. After that, the tax inspectorate, as an interested state body, must apply to the Federal Bailiff Service (in other words, inform them that you have such a debt), and already the bailiffs have the right to impose a ban on departure and send information about it to the databases of border guards who will "wrap" you at the border.
This whole procedure takes a lot of time, so do not panic if yesterday the deadline for paying the tax was missed, and today you are going on a long-awaited vacation or business trip abroad. In addition, there is a minimum level of debt, below which the ban is not established. This minimum amount is regulated by law (federal law "on enforcement proceedings" of 02.10.2007 N 229-FZ), and from October 1, 2017 is set at at least 30,000 rubles.