You don't have to pay any income tax on the rent you receive if:
you live in the same property as your lodger
the room you rent out is furnished, and
the rent you receive is not more than £7,500 a year (£625 a month)
If you get more than this amount in rent, you can either pay income tax on the amount over £7,500 or pay tax on all the rent and claim tax back on any expenses involved (such as buying furniture or providing services). For more information, read Rent a room scheme and tax and the Government's guidance on the Rent a Room Scheme.