If they do not they risk being hit with new fines starting at £1,000 and increasing up to £10,000 for repeat offenders or serious breaches, the Department of Health and Social Care (DHSC) said.
People who test positive for Covid-19 will also be fined if they knowingly provide false information about close contacts to the test and trace service.
The DHSC said that police will check compliance in the highest incidence areas and in high-risk groups based on “local intelligence”.
High profile and “egregious” cases of non-compliance will be investigated and prosecuted while action will be taken on tip-offs from “third parties” about people who have tested positive but are not self-isolating, the DHSC added.
But people on low incomes who cannot work from home and have lost income as a result will also be eligible for a new £500 test and trace support payment, it added.
From tomorrow, people in England will be required by law to self-isolate if they have #Covid19 symptoms, a positive test result or are told to by NHS Test and Trace— Department of Health and Social Care (@DHSCgovuk) September 27, 2020
That means no walks in the park and no meeting up with friends.
Read the guidance 🔽https://t.co/SAmTSBaGmbpic.twitter.com/WS5Oiz1f02
Under new rules in England wedding ceremonies will also be restricted to 15 people.
Meanwhile three more council areas in South Wales will go into local lockdown from 6pm on Monday, the Welsh government has announced.
Neath Port Talbot, Torfaen and the Vale of Glamorgan will be covered by the restrictions, which mean people will not be able to enter or leave the areas without a reasonable excuse.
They will not be able to meet indoors with anyone they do not live with, with extended households suspended.
Restrictions are already in place in Cardiff, Swansea, Llanelli,...