It is impolite to split the bill. The telephone is a useful tool to set up appointments and ask some general inquiries, but deals are never closed over the phone. Telephone is considered an informal means of communication. It is also recommended that you confirm all appointments over the phone. Cellular phones are pervasive in Mexico.
Fax machines are also very common.
They are preferred over the phones when dealing important issues. Remember that a spoken commitment in Mexican business culture is never binding. A Fax is. In most cases when phoning a Mexican businessperson, you will have to go through 1-3 secretaries before reaching the desired person. Hiring In Mexico, jobs can be advertised for man or woman, with an age range, and marital status specified as well.