it was rented and my landlord asked me to leave details of water and electric suppliers so that he could change it to the new tenants name. I’ve recently found out that this didn’t happen and that the new tenants have been getting their supplies in my name. The companies have told me that it was my responsibility to inform them of my move when i left and are trying to charge me. Could I get the new tenants done for fraud? I live in UK. Thanks

Against the tenants the theory is called unjust enrichment. Basically it means they got something for free which they knew was not free. You could also sue your landlord for negligence. You collect only once. You sue them both.