This is how the Catalan tax system will affect Catalans: they will be able to choose who they declare their personal income tax for in 2026.

In the first phase, the personal income tax return can be sent to one of the two tax authorities, which will exchange information. The process can also be completed using the Generalitat's digital certificate.

Catalan taxpayers will already notice in 2026 the agreement reached this Monday by the Government and the Generalitat (Catalan regional government) on the "bilateral" financing model , the main asset of which is the Catalan Treasury.

Catalonia has had a tax structure since 2006, which collects and inspects its own and transferred taxes. Its revenues are around €5 billion annually, compared to the €30 billion the State Tax Agency receives from personal income tax alone.

In terms of resources, the gap is also abysmal, both in terms of the IT equipment used to combat fraud and, most importantly, in terms of personnel. The Catalan Tax Agency (ATC) employs around 850 people, and is expected to soon surpass the 1,000-person threshold with the ongoing public employment calls. In any case, this figure contrasts with the 4,200 Treasury employees in Catalonia.

The agreement says nothing about what will happen to the tax inspectors , who are key to this whole issue. It leaves the details of the new system and its mechanisms to a working group between the two governments.

It is known how the Catalan Treasury will prepare to gain responsibilities. In the next personal income tax campaign , corresponding to this year and due to be settled in 2026, the agreement stipulates that Catalan taxpayers will be able to choose whether to submit their tax returns to the Tax Agency or the ATC.

Thus, "the necessary changes will be promoted" to make it possible to file declarations, and also "to enable the use of the digital certificate established by the Generalitat (IdCAT) in this filing," states the agreement signed by the two executives.

After this experience, the goal is "to be able to move forward progressively, as long as the legal framework allows," and to gradually incorporate other powers. Among them, "the verification of the correct application of regional regulations and, in particular, of the deductions approved by Parliament."

Regarding personal income tax, the two governments are opening the door to extending the agreement they reached earlier this year to jointly manage vehicle registration tax collection , which has yet to materialize.