In mainland China, a health code that dictates where citizens can travel has been mandatory since the pandemic hit. Meanwhile, Hong Kong’s contact tracing app doesn’t even know the user’s name.

That gap in surveillance has become a major sticking point in protracted talks about restarting quarantine-free cross-border travel, which could happen in a limited capacity as soon as December, the South China Morning Post reported late Thursday.

Earlier this month, Hong Kong Chief Executive Carrie Lam told a local news outlet that she had no plans to add a tracking function to the city’s LeaveHomeSafe app. But she also warned that residents would need to download their records if they wanted easier access to the mainland.