Visible crew/equipment: Every time the shot shows the chair between living room and kitchen (when they show where the chair is), the reflection of the studio light is seen on the bottom of the chair. For example, in Season 2, episode 2 "iStage an Intervention," when Carly looks at Pack Rat, when she walks, you can see the studio lights at the bottom of the chair,.
Continuity mistake: In "iPromote Tech Foots", Sam hires a personal chef, Sonia. When Carly, Sam and Freddie are sitting at the table and Spencer is talking to them, Sonia takes the blueberry muffins out of the oven and puts her oven mitts down. Next, Spencer starts walking away. Then Sonia is putting down her oven mitts again. There is no way she could pick up and put down her oven mitts that fast.
Continuity mistake: In "iPsycho", after Gibby is kicked into the stack of boxes, he slumps to the floor and a large sleeping bag or pillow appears beside him only to disappear in the following scene. Then when he takes off his shirt, a yellow extension cord appears on top of the boxes.
Visible crew/equipment: In the iCarly TV movie "iGo to Japan," the gang is riding in Kioko and Yuki's car when the Japanese comedians start arguing. In the shot showing Freddie putting his camera away, you can see several reflections on the side of the car. They are hard to make out what they are, but these are obviously the reflections of the crew in the background. If you look out the window beside Carly and Sam in the same shot, you can see how fast they are going past Tokyo. If these reflections are reflections of things in the city, they would quickly move away as they speed past. However, they stay put.
Other mistake: Season 1, episode 5 "iWanna Stay with Spencer": The "Fan of Hammers" has all the hammers pointed the same way. But when the hammer goes into the wall, it goes in backwards. It is also there through all the rest of the shows and even in season two, where in "iKiss" it has a black handle.
Plot hole: Near the end, Sam locks Mr. Howard and Ms. Briggs in a closet. Sam and Gibby then put a heavy desk right against the door and leave them stuck inside. Then later the two teachers are seen frantically controlling the students. How did they escape? They were inside a closet with the door locked on the outside and with a heavy desk against it.
Continuity mistake: Season 1, episode 18 "iPromote Techfoots": When they have the first meeting with the techfoot people, Sam is eating a sandwich. Every time the shot goes back to her and Carly, the amount of the sandwich she has eaten changes. Sometimes there is a bite taken, and then the next time there isn't a bite taken out of it.
Continuity mistake: Season 2, episode 20 "iFight Shelby Marx": In the beginning, Carly gets a bowl and fills it with popcorn up to about 2/3 full. The camera cuts to Sam, then back to Carly, and the bowl is barely full. The camera goes back to Sam then to Carly again, and the bowl is 2/3 full again. Freddie walks in, and the bowl is barely full again, which Carly now fills with popcorn.
Continuity mistake: In "iGo to Japan", when the iCarly crew, Spencer and Freddie's mom have to jump out of the airplane, Freddie's mom jumps out of the airplane with out buckling the parachute backpack in a rush to follow Freddie. But when everyone has landed, she is struggling to unbuckle and take off the backpack.