NO One can accidentally receive or be tricked into receiving the Mark of the Beast. When someone receives the mark of the beast, they do so, willingly, knowing what they're doing, they are worshipping the beast or his image.
The mark of the beast occurs in the middle of the tribulation period. Since the tribulation is a seven-year period, the mark of the beast will be required at the halfway mark or 3.5 years into the tribulation. In the tribulation, two very powerful individuals will gain incredible power. Both are empowered by Satan. The first one is a political leader (2 Thessalonians 2:1-4; Revelation 13;1-10) who is called the Antichrist. He is the leader of a future world government. The second beast is called the false prophet (Revelation 13:11-18; 19:20-21). He is a religious leader. This is the one who forces people to receive the mark “666” in order to buy or sell (Revelation 13:16-17).