An exequatur is an official permit from a state that allows a foreign consul to begin work on its territory.

In simple words:

1. The consul has arrived, but cannot work yet. He presented a consular patent (a document that he is a consul from his country), but the receiving party must say: “Yes, we recognize you, work.”
2. Exequatur is this “yes”. It is usually issued by the Ministry of Foreign Affairs. Often this is simply a letter or inscription on a patent.
3. As long as there is no exequatur, there are no consular rights. He cannot yet perform his functions: issue visas, help citizens of his country, certify documents, etc.