Hi,
It depends on the payment plugin.
Most of payment plugins have a "confirm url" in their configuration, it is for the redirection if the payment succeeded or failed.
There is also the generic "checkout | after_end" view that you can override if required.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.