ˌɛnˌaɪˈaɪ ɪz ðə dˈɪfɹəns bᵻtwˌiːn ɐ ˈɪntɹɛst pˈeɪmənts ðə bˈæŋk ɹᵻsˈiːvz ˌɔn aʊtstˈændɪŋ lˈoʊnz ænd bˈiː ˈɪntɹɛst pˈeɪmənts ðə bˈæŋk mˌeɪks tə kˈʌstəmɚz ˌɔn ðɛɹ dᵻpˈɑːzɪts.
NII is the difference between (a) interest payments the bank receives on outstanding loans and (b) interest payments the bank makes to customers on their deposits.