I rented a house to a couple in January 2018. The rent has been paid on time and the house is being kept well. However I have just discovered that the couple brought 2 additional people into the house a number of months ago. My belief is that they intended to do so from the outset as the rent was not sustainable for them. At the time of letting the house, I asked the couple whether the rent was affordable and they indicated that it was. So they are in breach of the lease. My thinking on the next steps is to meet with all 4 people in the house and to indicated that I want to regularise the situation with all parties signing a new lease. I believe one of the tenants (a student) may leave in May when his course finishes and I am thinking that from that point, I will tell them that I want a maximum of 3 in the (3 bedroom) house. My original ideas was to get 3 professional people sharing the house.
Any advice would be appreciated particularly from anyone who may have had a similar situation as a landlord.
Thanks in advance.