> ## Documentation Index
> Fetch the complete documentation index at: https://developers.vivara.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Confidence tiers

> How reliable a score is, and how a candidate moves from one tier to the next.

Every score comes with a confidence tier. The tier tells you how much of the data behind the score is backed by documents. It does not tell you whether the candidate is good or bad: that is what the results are for.

## The three tiers

| Tier | ID number | Income | Documents | What is calculated |
| - | - | - | - | - |
| **Basic** | Not provided | Declared | None | Solvency only |
| **Declared** | Declared | Declared | None | Solvency and delinquency |
| **Accredited** | Provided | Provided | All required | Solvency and delinquency |

> [accordion] Basic
>
> You only have the candidate's declared income. Vivara can tell you whether
> they are solvent, but not whether they appear in a delinquency register. Add
> the ID number and postal code to move to Declared.

> [accordion] Declared
>
> You have the candidate's income and ID number, as stated by the candidate.
> Both results are available, but they rely on what the candidate told you.

> [accordion] Accredited
>
> Every value behind the score is backed by a document: the ID document for
> the ID number, and the income documents for the income. Both results are
> available.

## Rules

* **A candidate with no income cannot be scored.** Income is the minimum for any tier.
* **A score is Accredited only when every value is accredited.** If any document is missing, the score stays Declared.
* **Tiers are not steps in a fixed order.** You can send documents first and the ID number later, or the other way round. The tier reflects what you have sent so far.
* **Documents change the tier, not the results.** Sending a document does not recalculate solvency or delinquency. If the document shows a different value, update the value and the score is recalculated.

> [!NOTE]
>
> Today, a document accredits its value when it is present. Vivara does not yet
> check the content of the document against the declared data. See [Coming
> soon](https://developers.vivara.io/tenant-scoring/coming-soon.md).

## Which documents accredit income

The documents depend on the candidate's employment situation:

| Employment situation | Documents |
| - | - |
| Employed | Employment contract or work history report (*vida laboral*), and last two payslips |
| Self-employed | Annual income tax return (Modelo 100) or quarterly return (Modelo 130) |
| Retired or pensioner | Pension certificate |

The ID number is accredited with the ID document (DNI or NIE).


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