Can I file the Modelo 210 without a Gestor?

As a general rule, yes — for standard cases, filing without a Gestor or Asesor Fiscal is generally possible. A standard case means: one property, self-use or straightforward rental, one or two owners, no unusual circumstances such as inheritance, partial disposal or special tax situations. Fiscaro is designed as a suitable alternative for standard cases: the wizard guides through all relevant data, calculates the tax under the applicable rules (DA 55 LIRPF / AEAT Manual Renta 2025 §7.3.4), and enables digital filing through the designated submission process. A Gestor or Asesor Fiscal is generally advisable for: multiple properties with different usage patterns, mixed use with complex expense deductions and extensive documentation, inheritance cases with multiple heirs and outstanding declarations from the deceased, capital gains on property sales, and special tax situations requiring individual assessment. The tax responsibility remains in principle with the taxpayer — regardless of whether a Gestor is engaged or a platform is used.