After being an HSBC UK customer for 8 years, they froze my account for being inactive/dormant after a few months (I hadn't used it in a while), and also froze my telephone banking for some reason. I don't currently live in the UK, so could not go into a branch in person to "verify my identity".
After calling for 6 months and repeatedly asking for a letter/code to unfreeze my telephone banking (in order to then re-open my dormant account), no letter came. When I called, the customer service agents could not confirm the address they were sending the letter to for "my security", because my telephone banking was frozen. I would later find out that they were sending the letter (WITH SECURE INFORMATION) to the wrong address. But they could not tell me this. If this sounds Kafka-esque and ridiculous and illogical, trust me, it was.
I went into an HSBC US branch and begged them to call the UK bank to get my account unfrozen. After an hour on the phone, we were able to get my telephone banking unfrozen, but not my dormant account reactivated, because they have bizarre address and ID confirmation policies (what they are trying to confirm, I don't understand, because all of the addresses are easily changeable either on their website or through my other banks).
No policies are consistent. None of their staff seem to know or understand their policies for basic things like unfreezing an account. I would absolutely NEVER recommend this bank to anyone. I will likely be closing my account after I get it unfrozen (it still isn't).