“It just goes to show [the] motherland’s strong support to Hong Kong [under] ‘one country, two systems’,” Ng told the Post at the CTS centre in Sheung Wan, referring to the principle governing relations between the city and the central government.

British national Steve Hart, also visiting the Sheung Wan centre, said he was looking forward to easier entry procedures, compared with those for his previous trips to the mainland.

“Everybody I speak to knows about [the new permit],” said Hart, who is in his early 40s and has lived in Hong Kong for 16 years. “I’m quite excited to try this method to get across the border.”

Other centres across the city also saw a steady stream of foreign nationals arriving throughout the morning.

Sanders Chung Tai-cheung, an 18-year-old Philippines-born Hong Kong resident, arrived at the CTS centre in Mong Kok with his mother before 9am to apply for the new permit for studying purposes.

“I know about the new permit and my school suggested that I apply for this for easier access to the mainland campus,” said Chung, who is studying media at Shenzhen University’s Hong Kong College.

“This permit will be a game changer as it allows me to have a faster border check multiple times.”

Chung told the Post he was not able to proceed with the application as CTS staff advised him to book another appointment after he was unable to provide a mainland phone number.

Other applicants said they did not provide a mainland phone number and were not turned away.

At the Mong Kok and Tuen Mun centre, the Post also spotted a notice informing people that if they applied for the new permit, their other forms of mainland visas would be cancelled.

Those holding Apec business travel cards are also unable to apply for the new permit, according to the notice.

But CTS Hong Kong chairman Perry Yiu Pak-leung said in the afternoon that based on his understanding, those with valid Apec business travel cards could apply for the permits as long as they brought all the required documents.

Announced on July 1, the permit will allow non-Chinese nationals with permanent residency in Hong Kong and Macau to enter the mainland for purposes such as short-term investment, visiting relatives, tourism, business, seminars and exchanges multiple times for a period of up to five years.

Permit holders can spend up to 90 days for each stay on the mainland and enjoy self-service clearance at control checkpoints once they have their fingerprints taken at ports of entry. Permits will be issued within 20 working days if their applications are successful.

Before its introduction, most of the city’s 270,000 adult non-Chinese nationals with permanent residency had to apply for separate visas to visit the mainland.

Chief Executive John Lee Ka-chiu has said the new measures would help to enhance Hong Kong’s “unique status and advantages”, while foreign business chambers have said the move would help reinforce the financial hub’s gateway role and international status.

Demand for the permit has surged, with bookings for appointments at CTS’ sole Hong Kong Island centre full until July 30, Other centres were fully booked until the end of this week, according to a check by the Post on Tuesday night.

Yiu, who also represents the tourism industry in the legislature, said he hoped the new permit could provide convenience for those looking to apply, especially students.

“We have a lot of young talent and students who may want to spend time and visit the mainland for summer holidays, join study tours or exchanges,” he said at the CTS Kowloon East centre.

“Considering how long and complicated it is for students to cross the border, we hope this new measure can be more convenient for them.”

But some foreign nationals found themselves turned away after being told they did not have the right documents.

Common issues observed by the Post included failure to book an appointment without a “Notice of Application for Access to Information”. Applicants are required to obtain the document that states their Hong Kong permanent resident status and nationality information from the Immigration Department before making an appointment.

Indian national Wesley Kotian, 59, a stay-at-home father, went to a service centre but did not know he had to apply for the document and make an appointment in advance.

“I thought I could just walk in and apply with my Hong Kong ID card,” said Kotian, who has lived in the city for 32 years.

Filipino Joan Dupitas did not have the document either when she arrived at the Mong Kong centre.

“It’s frustrating. The information is not clear for me because I don’t know I need the document,” the 44-year-old customer service officer said.

The CTS website states that applicants aged 11 or below who have not applied for a permanent ID card are also required to obtain the notice.

Additional reporting by Tom Shuai and Alice Kong