Must be Efficienze ipotecarie.
Has Google hits.

I assume the Italian 'efficencies' words is cognate with the Spanish affeciones or afectaciones meaning assignments or collateralisations.

Also depends on how oneri is translated: if charges, then use mortgage exposures for his one.

Mortgage inhibition is the way at the UK HM Land Registry to protect a mortgage, the parties being oddly called the inhibitor and inhibitee.