Tax Authority Tightens the Timeline: The 2026 Tax Changes Freelancers and SMEs Can’t Afford to Ignore

Every fiscal year brings its own rhythm of obligations with the Tax Agency, but 2026 is shaping up to be a year of structural change rather than simple calendar tweaks. The combination of mandatory e-invoicing, contributions for the self-employed now firmly based on real income, and closer data cross-checking by the tax authorities is forcing many businesses to rethink processes that had run on autopilot for years. These aren’t isolated updates: they’re pieces of the same strategy from the tax authorities to shrink the undeclared economy and shift oversight to the moment a transaction happens, rather than waiting for the return that follows it.

The most visible axis is the rollout of Veri*Factu and, alongside it, mandatory e-invoicing between businesses stemming from the “Crea y Crece” Law. The rollout timeline has been staggered by billing volume, but the intent behind the rule is clear: every invoice issued must be recorded in a way the tax authorities can verify, and invoicing systems that don’t meet the required technical standards will stop being valid. For SMEs and freelancers still invoicing through Excel templates or uncertified software, the window to update their systems is closing fast.

On the contributions front, the system that ties self-employed contributions to actual net income keeps moving forward, and 2026 brings a new twist: the first full-scale adjustments for already-closed tax years. Anyone who paid contributions based on a figure that didn’t match their real income will now face either a supplementary payment or a refund, depending on the case. On top of that, the yearly update to contribution brackets is worth checking every January, so you don’t spend months paying into a base that no longer matches your expected income.

As for the quarterly calendar, the usual deadlines remain in place for VAT (Form 303) and installment payments for personal income tax (Form 130) or corporate tax (Form 202), due within the first twenty calendar days of the month following each quarter’s close — except for the final quarter, which is filed in January together with the annual informative returns (390, 190, 347). The tax authorities have also stepped up cross-checking between what’s declared on these forms and what shows up in e-invoicing records, meaning any gap between what a business issues and what it declares is now far easier to spot — and far costlier to fix later, with surcharges that grow the longer the discrepancy goes uncorrected.

What this means for your business

In practice, this calls for concrete decisions now, not in the last quarter of the year. First, check whether your invoicing software already meets Veri*Factu requirements or is on track to — migrating with time to spare beats scrambling once the deadline is on top of you. Second, if you’re self-employed, review your projected net income for the year and adjust your contribution base before the gap between what you’re paying in and your actual earnings triggers an unwelcome adjustment. Third, lock down the reconciliation between what your business invoices and what it declares each quarter: mismatches that used to slip by unnoticed are now far more likely to trigger a request for information. And fourth, don’t leave the review of deductions and deductible expenses for income tax or corporate tax season — doing it quarter by quarter lets you catch issues in time and avoid surprises in the final bill.

At Zythos Business, we track these changes closely so our clients don’t have to decode them on their own: we make sure each business’s invoicing is ready for the new technical requirements, adjust contribution bases to match the reality of each activity, and reconcile every quarter before filing — so no tax authority update ever catches you off guard.