List of Errors

Episode	Error
Pilot	- Michael mentions he has a brother, but he is confirmed as being an only child later in the series.
Diversity Day	- Dwight makes Michael swear on his mother's grave, but his mother is still alive, as seen in a deleted scene from Product Recall and phone calls in The Injury, Night Out, and Customer Survey.
Health Care
The Alliance	- Meredith's birthday is the next one for the office staff, and it is more than a month away (Also see Survivor Man).
Basketball
Hot Girl
The Dundies
Sexual Harassment
The Fire
Office Olympics
Halloween
The Fight
The Client
Performance Review
Email Surveillance	- Michael mistakenly calls his character "Michael Scoon", instead of "Michael Scarn".
Christmas Party
Booze Cruise
The Injury
The Secret
The Carpet
Boys and Girls
Valentine's Day
Dwight's Speech
Take Your Daughter to Work Day
Michael's Birthday
Drug Testing
Conflict Resolution
Casino Night
Gay Witch Hunt
The Convention
The Coup
Grief Counseling
Initiation
Diwali
Branch Closing
The Merger
The Convict
A Benihana Christmas
Back From Vacation
Traveling Salesmen
The Return
Ben Franklin
Phyllis' Wedding
Business School
Cocktails
The Negotiation
Safety Training
Product Recall
Women's Appreciation
Beach Games
The Job
Fun Run
Dunder Mifflin Infinity
Launch Party	- Jim actually signs John Krasinski, not Jim Halpert on Meredith's pelvis
Money
Local Ad
Branch Wars
Survivor Man	- Meredith's birthday is after Creed's but within the same month (also see The Alliance).
The Deposition
Dinner Party
Chair Model
Night Out
Did I Stutter?
Job Fair
Goodbye, Toby
Weight Loss
Business Ethics
Baby Shower
Crime Aid
Employee Transfer
Customer Survey
Business Trip
Frame Toby
The Surplus
Moroccan Christmas
The Duel
Prince Family Paper
Stress Relief
Lecture Circuit Part 1
Lecture Circuit Part 2
Blood Drive
Golden Ticket
New Boss
Two Weeks
Dream Team
Michael Scott Paper Company
Heavy Competition
Broke
Casual Friday
Café Disco
Company Picnic