Recognizing the potential profits digital currency will bring to the country, Spanish authorities have labeled bitcoin and altcoin mining operations as “economic activities.”

This means that cryptocurrency miners and mining companies will soon be required to register and to pay tax—somewhere between 10 percent to as much as 47 percent of the value of the mined coins, Spanish language news outlet CriptoNoticias reported.

Mining has not been a taxed activity in Spain, but the National Directorate of Tax said “they have taken the view that mining is an economic activity.”

The government believes the tax will curb illegal activities related to digital currencies. However, it could also affect the profitability of mining operations, which could result in miners to quit.