The ticket sales on Hong Kong's high-speed rail link had problems days before it opens. Some said that it could only be a simple glitch, but others feared they might be on China's blacklist.

The vending machines at the new West Kowloon terminus could not read older home return permits, so fears started around the China Railway Corporation blacklist because it prevents those on it from using the rail operator's vast mainland network.

According to the South China Morning Post, the blacklist is currently applied only to Chinese citizens, but it would be extended among Hongkongers as soon as the Guangzhou-Shenzhen-Hong Kong Express Rail Link opens this coming September 23. A lawmaker said that public should be informed when this has been implemented.

A lot of buyers reported there's a problem with the system, and although business was at brisk at the counter, the suspension of the online system and issues with the vending machines brought complaints.

Mr. Kwok, who is holding a first generation home return permit, said he had no choice, so he bought a ticket at the terminus. But he also noted that "even the mainland's vending machines can't read the older generation home return permits."

Meanwhile, new immigrant Mr. Wong said he bought a ticket through the online ticketing system from the mainland, but he was told his purchase had been denied due to unknown reasons.

"I think the online payment failure I encountered showed that Hong Kong's ticketing network is still not fully integrated with the mainland system," he said.

Roughly 6.8 million Hongkongers are using home return permit on a regular basis. This is a travel document being issued by the mainland authorities for Macau and Hong Kong residents in crossing the border.

According to Ben Chan Han-pan, the vice-chairman of the Legislative Council's railways subcommittee and a pro-establishment legislator, it's not yet clear whether unsuccessful buyers are already on the mainland authority's blacklist or they are only experiencing system glitches.

China includes blacklist on their system to track untrustworthy people - such as those who are banned from using the train because of several reasons like ticket reselling, smoking, and "other behavior."

Chan noted that the government of Hong Kong should ask the mainland authorities to explain clearly how blacklist works so they could deliver the information to the public.

But whatever the case is, ticket sales are still falling below expectations. On Tuesday, 3,266 tickets were sold in which 1,654 were bought online, 319 over the telephone, and 1,293 at counters and ticketing machines. The sales started to go bumpy starting last Monday, with 7,079 tickets have been sold in advance.