The 22-year-old stopper started as a youngster with Chelsea before joining Millwall as an U18, emerging through the Lions’ academy ranks and taking in a loan with VCD Athletic at the back end of the 2022/23 season.
He joined Barnet in the summer of 2023, working with former Wings Goalkeeper Coach Craig Holloway, and enjoyed a loan stint with Erith & Belvedere last February.
Gillmore joiined Welling to provide another option between the sticks following an injury sustained to number one Rhys Lovett in October.