Many observers have had a sceptical attitude towards Chinese banks’ official disclosures of non-performing loans. A loan should be classified non-performing if the customer stops servicing the loan. Therefore, hidden problems in the loan portfolio would manifest themselves as a suspiciously low interest revenue. Using this simple idea, this column sheds light on the likely distribution of hidden non-performing loans in Chinese banks. It finds that loan quality problems became more commonplace in 2016. Surprisingly, hidden NPLs seem more common in strongly capitalised banks and large banks, but also in banks that rely on interbank funding.