MB3 38a: Can a Jew Who Accepted Shabbos Early Ask a Jew Who Did Not Accept Shabbos to do Work for Him (263:14-17)

If a person accepted Shabbos accidentally he can still do melacha but can't touch the Shabbos candles. Davening mincha after communal acceptance of Shabbos. Asking a Jew who hasn't accepted Shabbos to do melacha for you if he hasn't accepted Shabbos yet.