For tax purposes, TNI operates with fiscal number 0034.74.082. It pays taxes on salaries.

TNI is not considered an enterprise and as such is exempt from charging and paying VAT, save where clearly commercial activities might be involved. TNI did not undertake any such activities in 2020.

TNI is acknowledged by the Dutch tax authorities (RSIN: 3474082) as an organization that works for the common interest (ANBI: Algemeen Nut Beogende Instelling). This allows those who make donations to TNI to qualify for tax rebates within the European Union.

TNI has long been formally recognized as holding the equivalent of 501 (c) status in the USA, which status is reconfirmed annually with a certificate and which may be used by members of NGOSource.