Yes, the tax authorities consider your Friend contribution to be a gift. Furthermore, due to the Giving Act, you are also eligible for extra tax benefits by making donations to cultural institutions. Single donations are tax-deductible if the sum of them each year is higher than 1% of your aggregate income with a minimum of 60 euros. There is also a maximum amount; the total amounts of your gifts may not exceed 10% of your aggregate income.
If you wish to reap the maximum benefit of the fiscal advantages, then we suggest that you register your gift as a periodic donation. Periodic donations do not have a fixed minimum or maximum amount. However, there is a condition that states that you must donate the same amount each consecutive year for a period of at least 5 years, and you must register your gift in a donation agreement. Since 2014, it is possible to do so without a notary. The agreement is available for download here. Do you prefer a notarial deed? The mandate is available here. NDT will reimburse you for notarial fees for donations higher than 250 euros.
You can calculate your tax advantage yourself here. You can find more information at www.belastingdienst.nl