Goofs

In Season 1 Episode 4: The Alliance (2005), Michael asks Pam for upcoming birthdays and she tells him that none are coming up until next month and Meredith is the next person on the list. In Season 4 Episode 11: Night Out (2008), Angela tells Jim, "It's Birthday Month; after Creed, it's Oscar's turn, and Meredith's is at the end of the month."

Per IMDb rules, TV shows are free to change or rewrite back stories during the course of a series, especially ones that have been on for a number of years.

Although everybody who works at Dundler-Mifflin is used to the crew of cameramen and boom mic operators, few people outside of the office would be. Yet, most people act unaware of their presence, whether they are walking into the office, or if the camera crew follows members of the office somewhere, such as into a crowded restaurant, school or other offices. Most people's natural reaction would be to look directly at the camera or what is being filmed.

In the kitchen, a no smoking sign on one of the cupboards has "Sec. 6404.5" underneath. 6404.5 is the California Labor Code for smoking in the workplace. The series takes place in Scranton, Pennsylvania.

It's obvious that scenes filmed outside the office are shot in Southern California and not Pennsylvania due to the extreme differences between the two states.