Mongolia to Shanghai or Beijing by Bus

If you travel by bus, the 72 hour free transit cannot be used because the 72 hour policy is only applicable for flight travelers.
But if you enter Beijing by bus and stay there for less than 24 hours, no entry permit is required because you can use the 24 hour direct transit.
Otherwise, a transit G type or tourist L type is needed.

Thanks so much for getting back to me.

So to confirm, if I take a bus or train from the Mongolian boarder to the airport within 24 hours I don't need a visa?
Is it possible to get another Chinese visa from Mongolia to allow a slower journey?
Thanks again

Alice, if your layover time in PRC is less than 24 hours before the flight takes off, you can use the 24 hour direct transit in Beijing.
Of course, you can try to apply for another visa to enter PRC in Mongolia.