We’ve got an ongoing (*) case study on the Spanish local board (see Me he comprado un piso con bitcoin). A person from that board recently bought a flat in Spain, and paid using Bitcoin a sum that is equivalent to just 100K€. All legally backed, notary to testify and so forth, but … the amount that was actually paid in BTC was written down in the deeds as cash, rather than BTC.

It therefore seems slightly on the hush-hush side when Bitcoin comes into the equation, and the notary hinted (without detailing) that payments stated in BTC are rather troublesome. The flat was cheapish, and cash can still be used between individuals for large sums (as opposed to when one side is a company), although above 100K would have triggered further burocracy.

(*) I call this an ongoing case, since come 2021, the buyer will have to deal with her income/tax reports, and the 100K equivalent noted in the purchase as cash (which was really BTC) may bring surprises.