@ApriCat
But what do you do now that so much is online?
Not really too much of a problem yet as most people dying are elderly and internet banking etc is a pretty recent thing, so the age group more likely to die, being say 75+ still have lots of things in paper format as they're more likely to have not "opted out" of receiving paper bank statements, paper invoices, etc., and there are still some banks which have retained paper pass books for savings accounts etc or at least paper certificates for ISAs, savings certificates, etc. You usually have to actively provide an email address or register on an App for things to move over to being online only, and the current elderly are less likely to be doing that. Elderly paper are more likely to have a cupboard or drawers of paperwork and more likely to keep all paperwork, whether needed or not. It's just the way they are. (Speaking in general terms, of course some will be highly tech savvy and will indeed be paperless, but at the moment it's pretty rare).
Seen it a few times with middle aged people who've died, and, yes, it's harder, but it just means a lot more "manual" contacting of banks, requesting statements etc and building your own picture of the person's life. If they're mostly or wholly online, then there's more chance of a proper "audit trail" based on the bank accounts and less chance of untraceable cash having been used, so in some ways it makes it easier. At the end of the day, you know their wages or benefits have been paid into a bank account somewhere, so you can ask the employer or benefits agency for the bank details. You know they must have paid their rent/mortgage, utility bills somehow, so again, ask the landlord, mortgage firm, utility firms which bank was used to pay the direct debits. Once you have the "main" bank account where money goes in and out of, you can then start to trace the unusual transactions in/out to other accounts, buying/selling investments, etc. As I say, you're building up a picture. The "deceased" departments of banks, utility firms, employers, governmental agencies, etc can be surprisingly helpful once you've satisfied them that you have the legal right to request information (even more if you're willing to pay them for copies of documents you need!).
As an accountancy practice, the use of "electronic" document storage and retrieval is something else we're really hot on when talking to clients and it's a regular recurring topic in our client newsletters to highlight the risks of not taking your own soft copies of all relevant documents uploaded to at least one additional storage location, whether a portable hard drive or a separate online storage such as dropbox, and more importantly leave the location details and passwords with your will!