Antichrist will cause all to receive a number and without that number, no man will be able to buy or sell. Almost every nation on earth has a national ID card where everyone is issued their own personal number. They have been trying to implement one in the United States for years. It's called the Real ID Act.
Still, millions will survive. What of the tribulation saints? Will they be forced to take the mark? Many Bible authorities suggest it is impossible, and there are a growing number of prophecy teachers who believe the tribulation saints will also have the mark of God.
You may also find it disturbing to know how an administrative procedure can remove your children from you. In 1921 Congress passed the Sheppard --Towner Maternity Act that created the United States birth "registration" area (see Public Law 97, 67th Congress, Session 1, Chapter 135, 1921.) That act allows you to register your children when they are born.
An overwhelming majority of scholars say the mark cannot be forced, though scriptures state the mark will be necessary to buy or sell. The mark may contain a unique emblem or symbol that identifies each individual as an "authorized" citizen, and therefore purchases of goods, finding jobs, travel and other necessities may be simplified. Likely some kind of global ID system (biometric IDs) will be put in place before the mark is established. It is likely that many of those who do not possess the mark (who aren't already killed) will die of starvation.
Many people have seen the idea of identification (ID) cards as a conspiracy against the liberty of individuals; those on the Right have usually drawn on biblical prohesies to warn against ID cards, while those on the Left have feared the introduction of increasing government surveillance and control of workers.