Goof (revealing mistake): In several episodes (mostly from season 5 onward), you can see ceiling segments missing from the manor when low angle shots are used. The ceiling panels are in large square, sometimes rectangular segments that are able to be removed to position studio lights for certain shoots. In many scenes these are missing, revealing the open studio space above the set.
Goof (anachronisms): Throughout the series, stock aerial footage of San Francisco is used. The footage often contains the Embarcadero Freeway (I-480/CA-480) a structure that used to run along the San Francisco Bay north of the Bay Bridge. The structure was removed in 1991, a full seven years before the series started.
Goof (revealing mistake): In many episodes, when the front door of the manor is opened in an exterior shot there is clearly a solid wall behind it, however in the sets there is a long corridor behind the door.
Goof (revealing mistake): in several cases throughout the series the view seen through the attic window is inconsistent with the houses location (possibly the studio grounds).
Goof (revealing mistake): In several episodes, when the sisters are baking a pie, it is clearly visible that the pie crust is empty, even though the person baking the pie has poured in the filling earlier.
Goof (continuity error): The establishing shot of the Halliwell house shows Piper going in the door with a black umbrella with a white stripe around the outer edge. The next shot, from the interior, shows her hanging up a black umbrella with a floral print. This happened because the establishing shot comes from the original, unaired pilot but the interior scene was re-shot.
Goof (revealing mistake): When Piper freezes Jeremy the elevator freezes as well but it remains stationary when Jeremy unfreezes.
Goof (continuity error): Piper closes the box after she hands Jeremy his fortune cookie but in the next shot, it's still open.
Goof (continuity error): Phoebe's flashlight beam is seen lighting the attic when the attic door first opens. When the camera goes back to Phoebe the flashlight is at her side, facing down.
Goof (audio/visual unsynchronized): After Piper accidentally freezes Chef Moore and she goes to fill the baster with the port, we hear the sound of the baster being filled, but Piper never squeezes the bulb.
Goof (continuity error): When Roger tells Prue about the promotion he got, his green pen changes to the black pen that squirts ink.
Goof (continuity error): Prue is seen picking up a newspaper and we see part of the headline which has a photo next to it. As the scene progresses and different shots were used, the paper switches back and forth from the headline with a photo to the other side of the folded newspaper.
Goof (continuity error): In the bar, Prue transfers cream from the creamer magically without the cream being poured into her cup which is the way her powers worked throughout the series.
Goof (continuity error): The umbrella that Piper walks into the Manor carrying is different from the one she then hangs up.
Goof (continuity error): The leaves on the trees (green, colored, bare) keep changing in several scenes.
Goof (revealing mistake): As a chef, Piper would not have worn nail polish for her audition. She should have worn gloves and a hair net.
Goof (revealing mistake): When Phoebe looks in the mirror, Alyssa Milano's tattoo is visible which was covered up by make-up the first season.
Goof (continuity error): When Piper is walking up the sidewalk and into the house in her first scene, she's using a black umbrella with a white stripe around the edge. When she goes inside, the umbrella she hangs on the coat tree has an overall floral pattern.
Goof (factual errors): The documentary Piper is watching on the Salem Witch Trials says that the witches were burned at the stake. In fact they were hung at a place called Gallow's Hill. There was also no accused witch/woman that was struck by lightening trying to enter a church.
Goof (continuity error): When Phoebe flirts with Alec at Quake, she rests her head in her hand. In the following back and forth shots of her and Alec, her hand moves from her face to the tabletop and back.
Goof (crew or equipment visible): When the mailman morphs into Trudeau, you can see a crew member wearing a green shirt and sitting in a director's chair in a mirror.
Goof (factual errors): When the mailman forms a key with his finger, he forms a Schlage brand key, but the deadbolt from the inside of the door is a Kwikset brand deadbolt.
Goof (crew or equipment visible): In the scene when Prue walks in and see's the "morphed" Andy looking around the house. He starts walking towards Prue and you can see in the back right side of the screen someone sitting in the kitchen, even though the house should be empty.
Goof (continuity error): In future episodes, evil cannot even touch the Book of Shadows (barring special circumstances), without it flying away. The evil shapeshifter manages to get it all the way to the threshold before it fights back. And, later, the book is handed over to the fake Victor without any reaction at all from the book.
Goof (revealing mistake): Mark, a ghost, bumps into a handrail as he and Phoebe are leaving the hotel where she's gotten a new job as a bar psychic.
Goof (revealing mistake): Mark as a ghost can't turn on the television, but he can sit on a couch, ride in a car and has doors opened for him even though he should pass through all of these solid objects.
Goof (continuity error): When Piper gets kidnapped, Prue and Phoebe come downstairs wearing different clothes than what they had on in the scene before, upstairs.
Goof (continuity error): When Piper is talking to Andy in the parking lot, the same guy on a cell phone walks by twice behind Piper.
Goof (continuity error): Piper picks up the invitations to Prue's birthday party twice.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): When Prue meets Andy and his ex-wife in the restaurant, why did she ask if she was his sister? Prue grew up with Andy, surely she would know if he had any siblings.