To send a fax to Japan from the US on a traditional facsimile machine — just enter the number as follows:
( 81 ) is the country code for Japan, and you must dial 011 for the international access prefix to call from the U.S. Be sure to prefix everything with a “9” if you normally do to access a line outside of your company’s phone switch.
It may be necessary to insert a pause in your dialing sequence after the “011” to allow the phone network time to connect you to an exchange. This differs between fax machines, but may be a comma or “#” sign inserted into the number.
If you receive a bad connection, you may have to lower the baud rate on your machine to ensure a noise free transmission. Give 9600 baud a try if the first attempt fails.
Dialing Japan can certainly be expensive. If you do it often it would be best to use an international phone card or join one of the online fax services for a free trial then cancel if you no longer need the service.
Another option is to sign up for a fax to email service such as Efax or MyFax. These services allow you to send unlimited international faxes simply through your regular email for cheaper than a single long distance phone call to Japan or Asia.