Jeff Layman wrote:

https://my.edfenergy.com/gas-electricity/tariff-information-labels/

Enter any valid postcode. Select cash/cheque as payment method, then
click on "Apply filters", Then Cash/cheque Whole Amount (Quarterly).

Quite a few tariffs will appear (eventually - it's a slow website).

So slow I'd have given-up and gone elsewhere

only a 1.5p/kWh 'sting' for quarterly cheque vs monthly direct debit.