In 2016, Thomas Spaas founded the law firm CONSYSTA, offering strategic, regulatory and compliance advice, in the fields of taxation and blockchain / cryptocurrency technologies.

Before, Thomas Spaas had been active in the legal field since 2005, first as a consultant for Belgian and European clients in Antwerp (BE) and Shanghai (CN) and subsequently as a lawyer at Tiberghien, at Laga (attorneys aligned with Deloitte) and at MVRV CVBA.

Working in the field of international and Belgian taxation, Thomas Spaas has built up broad experience in analysing and resolving international and Belgian tax issues and recommending tax strategies. He also assist clients that are confronted with tax controversies.

A second main area of expertise of Thomas Spaas are the law and regulations pertaining to cryptocurreny and blockchain technologies. Since 2013, Thomas Spaas has been assisting the Belgian and European bitcoin and blockchain-tech community, both in his capacity as a lawyer, and as a (co-)director of the Belgian Bitcoin Association ASBL.