1.
for yourself :
In 1992 Smith set up in business on his own account.
2.
because you want to and you have decided, not sb else :
No one sent me, I am here on my own account.
ON YOUR OWN ACCOUNT
Meaning of ON YOUR OWN ACCOUNT in English
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005