I heard on a podcast called "The Property Podcast" that the law is changing regarding ASTs (Assured Shorthold Tenancies) which means that even if your contract says you have to pay for at least 6 months, you can give 2 months notice at any time. Meaning you could stay for 2 months only if you gave notice on the first day. I was unable to find anything clear on the internet about this so I'm not sure if it is true?
I haven't listened to the podcast, but this is probably referring to the anticipated "Renters Reform Bill". A white paper was published on 16 June 2022. There is no Bill before Parliament yet, so the mooted changes are quite a long way from happening. (Additionally, the usual political churn may mean that this does not happen at all. The Secretary of State has already changed, and will likely change again once there is a new Prime Minister; political priorities may shift in all sorts of ways; there could be a general election; etc.)
One proposal from the government is (section 3.1):
We will abolish Section 21 evictions and simplify tenancy structures. To achieve this, we will move all tenants who would previously have had an Assured Tenancy or Assured Shorthold Tenancy onto a single system of periodic tenancies. Tenants will need to provide two months’ notice when leaving a tenancy, ensuring landlords recoup the costs of finding a tenant and avoid lengthy void periods. This will provide greater security for tenants while retaining the important flexibility that privately rented accommodation offers. This will enable tenants to leave poor quality properties without remaining liable for the rent or to move more easily when their circumstances change, for example to take up a new job opportunity. Landlords will only be able to evict a tenant in reasonable circumstances, which will be defined in law, supporting tenants to save with fewer unwanted moves.
Currently, tenants on an AST cannot leave their tenancy during the fixed term, unless the tenancy agreement specifically provides for this with a "break clause". A break clause might say that after six months, the tenant is allowed to terminate the arrangement with one month of notice to the landlord. Or there might be no break clause at all, so that the arrangement can end early only if the landlord and tenant agree ("surrendering the tenancy").
Once the fixed term ends, it can be renewed for another fixed term, or terminated, or else it rolls on to become a "periodic tenancy", typically month-to-month. The tenant can give notice to quit during this time. The government's proposal seems to amount to having no initial fixed term, but a statutory periodic tenancy from the get-go.
As far as timing, the white paper says:
We will provide at least six months’ notice of our first implementation date, after which all new tenancies will be periodic and governed by the new rules. Specific timing will depend on when Royal Assent is secured. To avoid a two-tier rental sector, and to make sure landlords and tenants are clear on their rights, all existing tenancies will transition to the new system on a second implementation date. After this point, all tenants will be protected from Section 21 eviction. We will allow at least twelve months between the first and second dates.
Again, the Bill has not been introduced to Parliament or even published in draft, so Royal Assent is a long way off.