> "They didn't send any money but both of them said it was incredibly difficult to keep what I'd told them in mind because "what if it really was you needing help?"
Perhaps a pre-established code phrase is a good way to address this. "If I ever need help, I will mention that [memorable vacation] we spent together. If that vacation isn't mentioned explicitly, it's not me."
Fine as long as your parents aren't beginning to go senile when such instructions will just be confusing and/or completely forgotten.
There might be better protocols - make sure all their cash is in the bank, set a per store per week limit of £200 on their cards, require your/siblings authorisation to make larger purchases?
But then there are things like their pensions, who they move their phone/internet account or other utilities to, so much opportunity for malicious people to commit fraud and deception; companies aren't motivated to help as it often reduces the companies income.
This is exactly what I have done when we leave the country. We leave a binder with emergency info including code words with expected responses to validate that our emergency contact at home is truly speaking with us.
Seemed kind of silly at the time but it truly is a low cost way to mitigate this issue.
Perhaps a pre-established code phrase is a good way to address this. "If I ever need help, I will mention that [memorable vacation] we spent together. If that vacation isn't mentioned explicitly, it's not me."