HSBC and its subsidiary Hang Seng Bank had resumed mobile phone service operations by lunchtime Monday after an earlier outage had locked customers out, but some online services were still temporarily unavailable, according to messages posted on the two lenders’ apps.HSBC, the biggest lender in the city with over 7 million customers in Hong Kong, had its mobile banking service interrupted, with many customers complaining they could not log on to the system on Monday morning.More than 10 HSBC customers contacted the South China Morning Post saying they were unable to log into the mobile banking since 9am.The mobile banking app showed a message saying “access is restricted until we have your valid email address and mobile number,” even though the customers already had their mobile phone numbers and emails in the system.In some cases, customers saw different messages, saying the app was “temporarily unavailable” and asking them to “close the app completely and try again later”.“We are working to resume normal functionality, as some customers may be experiencing difficulties accessing some of our services. We are resolving these as quickly as possible and apologise for any inconvenience caused,” an HSBC spokesman told the SCMP in a statement issued at 11am.