Is OVOs Simpler Energy (flexible, rolling contract) the OFGEM controlled 'default tariff price cap' plan?

Yes

Ofgem are due to announce the update around 26th August unless anything changes. 

The actual cap changes in October. 

Going forward the cap will change every 3 months rather than every 6 months.

The next prime minister is likely to tweak the cap (e.g. remove VAT and or green levy) but this may or may not impact the Oct cap. 

Thank you very much I believe this is the route I must follow when my current plan expires in September as OVO’s proposed new plans want 3 times the current Direct Debit level £560 to £660 PM and I feel double is adequate on what I know.

Thank you again all ver confusing I am not even sure that the year they quote is my Sept 4th to Sept 3rd and when I send a message it either does not get answered or answer about a different question all in all it all seems to have got worse of late I expect them to check “what” they are telling me about my fate is correct or they will start losing customers I have been withOVO for many years always with plans but this years real lack of support is raising questions about the future but “paying as yo go” with OFGEM Tariff control seems to be the way ahead with all this uncertainty.  Bu Thank You again