Hi Perdita
this is what the government website says
"
DWP offers email communication as a reasonable adjustment to disabled customers who require it.
Disabled customers who think they would benefit from email communication should contact us using the details on the last communication they received from us, or let us know when they next get in touch.
We’ll work with the customer to find out whether email is the most suitable means of communication. If it is, we’ll let them know how we’ll set it up for them."
There isn't one that is given out
Nothing on this board constitutes legal advice - always consult a professional about specific problems