Yes you need to register (in actuality you register the tenancy, not the landlord) with the PRTB.
You also need to deregister for Tax relief at Source on your rental property if you are claiming it (you know you are only entitled to claim TRS on your PPR, ie, one property only?) but you can offset all mortgage interest against rental income for tax purposes so it's no loss really.
The forms for registerering the tenancy and deregistering for TRS are availabe from www.prtb.ie and www.revenue.ie respectively.
You should not forget to inform your insurer of the change of use from (holiday home/PPR) to rental property as most all policies are only for owner occupiers an they could walk away if your property burnt to the ground.
Strictly speaking your bank should probably be informed so they can jack the interest rate up but I'll leave you to decide on that score ;-)
Thanks for the reply it has been a great help I have downloaded the prtb form and will cancel the tax relief and apply for it on my other home as it will be my main residence thanks again
Re: New to letting: have a 2nd house which I may let to a family friend on rent allc
make sure you have a lease and get 1 months rent in advance plus 1 month's rent as deposit. It is much easier for tenant to go into default mode if related as there is always teh heartstrings to be tugged at.
I have been in that position and if had chance again, woudl NOT rent to relation.