I want to know how can I get a key to POS software version 12.16?
You have to get in touch with the developers and have a QQ account in order to obtain the price for the software and a registration key. On the official website there is no price specified or ways you can use to buy it, but I believe the developers will provide this information after you get in touch with them.
Access the official page using the following link: http://www.shopspeed.com.cn/en/ProductDT.aspx?ID=14
