I have a bank account with TSB and got compensation as a result of this mix-up.<p>Some rather personal experiences of the fiasco:<p>– Rather pointlessly, the website changed from being mostly static to entirely written in a very JS-heavy, "dynamic" way. I still can't use it in my normal browser (FF) with its extensions because it relies heavily upon CORS requests and referrer information that my somewhat privacy-paranoid extensions block.<p>– This was introduced at the time of the switchover, and until that point the IT system used looked identical between Lloyds, TSB and Halifax / BOS systems (I have accounts with some of those)<p>– The online browser-based system was telemetry and JS heavy, replacing a far leaner page<p>– I was unable to log in during the time of the fiasco, mostly due to 403 errors or timeouts. Often the page would just hang as an async request wasn't answered.<p>– Once I did manage to log in, I was amazed to see another person's account details (!!!), replete with (their) name and statement.<p>– I was unable to use online banking to pay bills or check my balance – I could see someone else's account in detail but was too honest to do anything with that knowledge. I can't remember if my card stopped working but I was effectively forced to make other arrangements for quite an extended period of time.