James Foice, managing director of ASAP, said the decision was taken after a successful introduction of the accreditation, with 98% of members expecting to complete the programme by November.
The aim of the QA programme is to create an internationally-recognised serviced apartment standard.
"Members recognise the importance of legal and statutory obligations, health and safety and that any property is accurately and appropriately marketed, and this provides a high level of confidence for guests booking a serviced apartment."
Foice added that he has been talking to agents wishing to support the accreditation scheme by only offering ASAP-accredited apartments to their clients, as well as introduced the standard to a serviced apartment operator in Amsterdam.
"We encourage agents, and indeed all other channels in this fast-growing sector, who wish to work with quality assured ASAP operators to contact us, as our long term aim is to make ASAP QA the "kitemark" for the wider serviced apartment sector in the UK and beyond."
Founded in 2002, ASAP represents 74 members operating more than 14,000 apartments across the UK and Ireland.