SINGAPORE - The Housing Board (HDB) website experienced glitches on Tuesday (Nov 17), the day it launched more than 5,700 Build-To-Order (BTO) flats for sale.

Affected users took to Facebook and Telegram BTO group chats to air their complaints, with at least 50 complaints posted on HDB's Facebook page on Tuesday night.

Most of the Facebook users who complained said they were unable to make payment of the administrative fee to apply for a flat or were unsure if their payment went through.

The administrative fee is $10 for eligible applicants and $20 for parents and their married child who apply under the Multi-Generation Priority Scheme for two flats.

On the BTO application page on HDB's website, a message says: "Due to the heavy traffic, you may experience slow response from the system. Please try again later."

At 8pm on Tuesday, the HDB said in a Facebook post that it is aware that "some flat applicants are facing issues when submitting their BTO/SBF (Sale of Balance Flats) applications online" and apologised for the inconvenience caused.

It added that it is working to resolve the issues.

"Applicants with unsuccessful payment records and/or did not receive any confirmation email are advised to try again later," said HDB.

It also reminded interested applicants that the sales exercise is on for a week until Nov 23.

"Successful applicants will be determined by a computer ballot, and not on a first-come, first-served basis," said HDB.

On Tuesday, the HDB launched a total of 5,795 BTO flats across seven housing projects in five estates in the final sales exercise of the year.

It includes the highly-anticipated Bishan Ridges, where 1,502 two-room flexi, three-room and four-room flats are on offer on a site within walking distance of Bishan MRT station.

There are also another 5,220 flats on offer in this year's first and only Sale of Balance Flats (SBF) exercise. The previous SBF sale, which was typically held in May, was delayed due to the Covid-19 pandemic.