The round involves the last 32 teams in the competition.
There are 12 replays from the 32 3rd round games
Already Everton, Birmingham, Bolton and Blackburn have been knocked out by lower division opposition and Aston Villa and Sunderland lost in all Premiership ties. Two more Premiership teams will be out after their replays against fellow Premiership clubs.
Arsenal, Mau Utd and Chelsea join City as confirmed teams in round 4.
At least 8 Premier League teams will be out of the competition with a couple more facing tricky replays.
Swansea are still in the hat but they face a replay at non league Havant and Waterlooville after their draw at the Liberty yesterday.