Hi,
As you are receiving the rental income from the Airbnb business you will need to declare this to us. If you already file a Self Assessment tax return this needs to go on the SA105 UK property page.
Alternatively, depending on your circumstances you may not need to complete a return and can send a breakdown of income and expenditure to us after the end of each tax year. You can check whether you need to submit a return here:
Check if you need to send a Self Assessment tax return
Thank you.