My answer is as follows:
There are 2 (TWO) 12593 options, the first 1, for 1 Y per month allows cheapish international calls, the other allows you to roam outside of shanghai with a shanghai number and allows you to make cheaper calls and ALSO pay less to receive calls, again 1Y per month.
This 2nd 12593 , with this plan, you pay 0.49/min when roaming and calling and 0.30RMB/min when you receive calls. If you don't do this, receiving calls under the original plan would cost you $0.6RMB/min PLUS $0.07RMB PER 6 seconds.
If you have an M-Zone card rather than Go-Tone or Easy Own, then if you activate DDDIP it automatically enables 12593 outgoing.
To activate the first 12593 you can call them, or send KTXGX to 10086, or if I activated "DDD IP" then it also seems to activate 12593 calling, you can do this online also...
The first step is that you have to activate the DDDIP option, then you can add the 12593 options.
DDDIP 17951 send IPYH to 10086
Outgoing 12593 send KTXGX to 10086
Roaming calls - send KTMYB to 10086
some other options you can do it yourself at
- it has basic services in english, you will need the mobile number, account password ( from the card you got when buying the sim )
If you lost the password, then you are in trouble unless you registered the sim at a china mobile office and your best option is to buy a new card. They used to send you your password by sending MMCX, but that is now disabled because too many phone thiefs did that immediately and then turned the phone off, they are now in control of your phone account !
After logging in click on Service Handling, then click Other Services.
The top 3 options are DDDIP - which is the 17951 option , cheap long distance calls to outside of shanghai
12593 - which is the domestic Roaming option,
The 3rd option is DATA packages, if you do a lot of web browsing, or maybe emails, you should take one of these.
Mobile Data RMB 5 Package(30 M) CNY 5.00/month
Mobile Data RMB 20 Package(150M) CNY 20.00/month
Mobile Data RMB 50 Package(500M) CNY 50.00/month
Mobile Data RMB 100 Package(2G) CNY 100.00/month
Mobile Data RMB 200 Package(5G) CNY 200.00/month
4th option is a 2 rmb for 10 mms messages, useful if you ship pictures around, otherwise they are 0.3 Y per message.
( 10 for the price of 6 )