Tate, known in the UK for roles on The Catherine Tate Show and Doctor Who, appeared as boss Nellie Bertram in the second half of the comedy's latest season.
A source told TVLine that Tate is poised to return to the ninth season as a full castmember, though no official announcement has been made.
Show stars including John Krasinski, Rainn Wilson and Jenna Fischer will be returning this fall.
Mindy Kaling, who played Kelly Kapoor on the programme for eight years, has left to headline her own show The Mindy Project on Fox.
NBC bosses have said that the coming series of The Office will be something of a reboot, with new characters expected to appear.
Watch a promo for Catherine Tate's original appearance in The Office below: