Methodology

The verified-value rule

Every regulatory or market figure on this site is stored as a verified value: the number itself, the source document, the authority that issued it, the date it takes effect and the date we last confirmed it. A figure that cannot carry all of those is not stored, and therefore cannot be displayed.

This is enforced in the data layer rather than by editorial habit. An unverified value is represented as absent, and the interface renders an explicit “not yet published” state in its place.

How the calculators work

The calculators are arithmetic engines, not advice engines. They operate only on the inputs you provide, and they do not carry default tax rates, interest rates, yields or price assumptions. Where a field is left empty because you do not yet know the applicable rate, the tool treats it as zero and tells you that the result is therefore incomplete.

Each tool lists its assumptions and its formula so the output can be checked by hand. Results are estimates based on your inputs; they are not quotations and not tax calculations.

The location publication threshold

Location pages answer the same nine questions in the same order. A location page is published as a full data page only once at least six of those nine indicators have been verified and dated; below that threshold, the page presents what exists and marks the remainder as awaiting verified data. We would rather show six honest indicators than nine confident guesses.

Dates on the page

Three dates can appear: when the page was first published, when its content was last updated, and when its underlying figures were last verified. They are distinct, and the third is the one that matters when you are relying on a rate.

Limitations

Spanish property taxation is regionally set and changes without warning; municipal charges vary street by street; lending terms are individual to the borrower. Nothing modelled here can replace a quotation from a lender or a calculation from a Spanish tax adviser instructed on your circumstances.