Both brands were registered on 11 October and join Zephyr Homeloans, already listed to the Bristol Computershare headquarters address.
The firm is currently recruiting a commercial underwriter to the Bristol head office.
Both lending brands are registered under a class 36 registration, listing their duties as lending across all types of loans, including buy to let, consumer and commercial, lifetime and shared equity loans.
Computershare originally bought Topaz from RBS in 2015 and is using its HML subsidiary, which it bought the previous year in 2014, to help service mortgage portfolios.
Computershare was founded in Melbourne in 1978 and listed on the Australian Securities Exchange in 1994 but arrived in the UK in 1995.
The firm employs over 16,000 people across 90 offices around the world.