It means there'll be no mixing of households or support bubbles in indoor settings - while the 'rule of six' remains for outdoor settings.
It comes as the city of Nottingham continues to have the highest coronavirus infection rate in England.
new cases recorded in the seven days to October 9th
The latest data shows Nottingham now has a rate of 834.2 cases per 100,000 people - that's a huge jump from the 314.5 per 100,000 figure being recorded in the seven days to October 1.
Nottingham remains well ahead of the area with the second-highest rate in England, Knowsley, which is now on 656.9 cases per 100,000.
What do the tiers mean and what are the new restrictions?
The new restrictions imposed are part of a new three-tier system of local lockdown measures for England aimed at curbing a rising in national Covid-19 rates.
Nottinghamshire will be placed on 'high' level - Tier 2.
The "rule of six" preventing most gatherings of more than six people indoors or outdoors, the 10pm curfew on pubs and restaurants and other existing national measures will continue to apply. The Prime Minister said this will cover most of the nation at the moment.
All mixing between households and support bubbles will be prohibited indoors. But meetings of up to six people will be allowed outdoors in public spaces and private gardens. The PM said "most areas" already subject to local restrictions will be in this level but so will Nottinghamshire.
Pubs and bars will be forced to close and "social mixing" indoors and in private gardens will be banned at the minimum. Groups of up to six people could still be permitted to meet outside in public spaces. But additional restrictions will be imposed based on discussions with local leaders, including those that could cover the hospitality, leisure, entertainment and personal care sectors. Schools, shops and universities will remain open.
Areas across the Midlands that have already had increased restrictions imposed, such as Birmingham, Leicester and Wolverhampton, will all move to Level 2 of the new tiered system.