Caledon1297
pfm Member
Not sure what this can be, as d.d. IS variable. My contract is a fix but I could, I'm sure, increase it if I wished. Octopus would certainly do so if I started bingeing on energy.
It's payment in arrears - you submit meter readings, which generates a bill, and a DD is taken for the full amount of the bill, which will vary month to month (or quarter to quarter, depending on the frequency of submitting meter readings).
Presumably, what you are paying is called 'fixed' DD, even though the amount can be increased/decreased, depending on your actual usage over time and/or wholesale costs (as many are now experiencing…).