Amounts retained by non-resident tour operators/intermediaries from payments made by foreign tourists for tourist facilities provided in Zimbabwe constitute 'fees' from a source within Zimbabwe for purposes of section 30 of the Income Tax Act and the Seventeenth Schedule, regardless of where the payment transaction occurs. The 'source' of such fees is Zimbabwe because the 'originating cause' of the income is the tourist facilities and services provided in Zimbabwe by the resident service provider. The term 'fees' in paragraph 1(1) of the Seventeenth Schedule, defined as 'any amount from a source within Zimbabwe', is broad enough to include commissions, discounts, or any diminution of the rack rate retained by intermediaries. The deeming provisions in paragraph 1(2)(c) apply where fees are 'so dealt with that the conditions under which the payee is entitled to them are fulfilled', even if never physically received by the resident payer. ZIMRA may invoke section 45 to estimate fees where the taxpayer fails to provide returns or where information is available (such as rack rates and net rates received). The resident service provider is obliged to withhold and remit NRTF on such fees within 10 days of invoicing the intermediary.