HMO licence in Islington confusion

HMO Licensing

Hi all,

My first post here, so hope I'm doing this ok. 

I'm about to apply for a HMO licence with Islington Council for a property on Caledonain Road.

The properties are above a shop and comprises of 4 self contained flat. 3 of which are let out on shorthold tenancies and one which is on short lets. 

I'm confused on which licence I need to apply for. I'm assuming its the 257 Property Licence - would i be right? I'm not 100% sure. I'm new to HMOs and it breaking my brain trying to fully understand!

These are the criteria for 257 Licence :

• The building (or part of it) has been converted into self-contained flats
• The conversion did not comply with the relevant Building Regulations in force at the time of conversion and still does not comply
• Less than two thirds of the flats are owner occupied (more than one third on short tenancies).

Does that mean if it needs to fit all above criteria, or just one?

Sorry if I've not been clear with my queries. Still trying to wrap my head around all this. 

Thank you