Portugal's Tax Court Backlog Has Halved Since 2020, Yet a Dispute Taken Through Three Courts Can Still Last More Than a Decade

The number of tax cases waiting in Portugal's first-instance administrative and tax courts has more than halved in five years, from 39,912 at the end of 2020 to 18,480 at the end of 2025, a fall of about 54 percent. But a taxpayer who takes a dispute through all three levels of court "can expect to wait more than 10 years for a final decision", and the southern appeal court will need until 28 February 2031 to clear its tax backlog at its current pace. The figures come from "Portugal Fiscal", a study published on 27 October by the Fundação Francisco Manuel dos Santos and written by Sérgio Vasques, Susana Peralta and José Pedro Sousa from the annual reports of the administrative courts' council (CSTAF).

Where the cases are stuck

At the end of 2025, 26,942 tax cases were pending across the administrative and tax courts. The Lisbon Tax Court had 5,384 of them and the Central Administrative Court South (Tribunal Central Administrativo Sul), the appeal court for the south, had 5,987 in its tax section.

"Disposition time", the time a court would need to clear every pending case at that year's pace, ran at first instance from 193 days at the court in Mirandela to 1,232 days in Ponta Delgada, with 538 days at the Lisbon Tax Court, the busiest. At the southern appeal court it reached 1,884 days, more than five years.

The authors credit the decline to fewer new cases, more judges, recovery teams and the diversion of disputes to arbitration. They still call tax justice "one of the most problematic areas" of the system: under pressure, courts "often opt for formal or poorly studied decisions", and many taxpayers accept assessments they think are wrong rather than litigate for years.

Arbitration now takes a third of disputes

Tax arbitration at the Centro de Arbitragem Administrativa (CAAD, the Administrative Arbitration Centre), available since 2011, now handles more than one in three challenges taxpayers bring against the tax authority, the study finds. Arbitral decisions take 4.5 months on average, and taxpayers won 60 percent of arbitration cases in 2025. CAAD received 1,130 requests in 2025, against 1,424 the year before.

If you want to dispute a tax bill

• Administrative complaint first. A reclamação graciosa to the tax authority (AT) can be filed within 120 days, under Article 70 of the tax procedure code (CPPT), usually counted from the end of the payment deadline.
• Court. A court challenge (impugnação judicial) must be filed within three months under Article 102 of the CPPT.
• Arbitration. A request to CAAD must be lodged within 90 days of the same starting points, under Article 10 of the arbitration law, Decreto-Lei n.º 10/2011. The decision is due within six months, extendable by up to six more, and appeals are possible only on narrow grounds.
• Cost. Under CAAD's fee rules, the fee depends on the amount in dispute, with a minimum of 306 euros when CAAD appoints the arbitrator; half is paid upfront and the final split is set in the decision. Choosing your own arbitrator costs between 6,000 and 120,000 euros, paid in full by the taxpayer. Disputes above 60,000 euros go to a panel of three.

Time limits are short whichever route you take, so seek advice as soon as an assessment arrives; councils have also been using tax enforcement to chase school lunch debts. For property tax, a revaluation request may avoid a dispute altogether. Ordinary courts also had more than 27,700 cases waiting over four years at the end of 2024.