Methodology
Updated on
This page explains where Leiloeiro's information comes from, how we handle it and where it can fail. We prefer to state the limits than to promise what we cannot deliver.
1. Where the data comes from
Every property we show comes from notices published by official and private entities, on publicly accessible pages. The list is in Sources.
We do not accept notices sent by private individuals, we do not create notices and we do not receive payments to give prominence to properties.
2. How we collect
Collection is done by our own automatic program, which:
- identifies itself in every request, with the Leiloeiro name, an address with information about the collection and a contact;
- respects the robots.txt file and the terms of use of each source. Before following a source, we read and record those rules;
- limits the pace of requests: as a rule, at most one request every two seconds per source, with longer pauses when the source is slow or returns errors;
- does not get around barriers: it does not use anyone's credentials and does not go past sign-in pages, human-verification tests, paid areas or geographic blocks.
If a source only makes its notices available in a restricted area, or if its rules do not allow automatic collection, we do not collect from it until there is authorisation. In that case, the coverage table says so, and we point to the official website.
3. How often we check
How often each source is checked, when collection is active:
| Source | Frequency |
|---|---|
| Portal das Finanças (Autoridade Tributária e Aduaneira, the Portuguese Tax and Customs Authority) | Twice a day |
| e-Leilões (OSAE, the professional body of solicitors and enforcement agents) | Four times a day. Hourly in the last 24 hours of auctions followed by users |
| Segurança Social (social security) | Once a day |
| Auction houses and banks | Once a day |
| INE, Statistics Portugal (median value per m²) | Quarterly |
| CAOP, the official administrative map of Portugal (administrative boundaries) | Yearly |
Each property page shows the date and time of the last check. Between two checks, the official notice may change.
4. Coverage by source
The following table is updated automatically. It shows, for each source, whether collection is active, the date of the last successful check and the number of notices being followed.
| Source | Status | Active properties | Last successful collection |
|---|---|---|---|
| Portal das Finanças (Autoridade Tributária) | Not covered yet | 0 | — |
| Avalibérica | Not covered yet | 0 | — |
| C. Paraíso | Not covered yet | 0 | — |
| Justa Venda | Not covered yet | 0 | — |
| LC Premium | Not covered yet | 0 | — |
| LeilOn Ativos | Not covered yet | 0 | — |
| Leiloport | Active | 21 | 12 November 2026, 14:52, Lisbon time |
| Leilosoc | Active | 42 | 12 November 2026, 14:52, Lisbon time |
| Leiloversatil | Active | 7 | 12 November 2026, 14:53, Lisbon time |
| OneFix Leiloeiros | Not covered yet | 0 | — |
| Vamgo | Active | 20 | 12 November 2026, 14:53, Lisbon time |
| Caixa Imobiliário (Grupo CGD) | Not covered yet | 0 | — |
| Parvalorem, S.A. (imóveis ex-BPN) | Active | 15 | 12 November 2026, 14:54, Lisbon time |
| Imóveis Santander (Banco Santander Totta, S.A.) | Active | 35 | 12 November 2026, 14:54, Lisbon time |
| e-Leilões (OSAE) | Not covered yet | 0 | — |
| Segurança Social (IGFSS) | Not covered yet | 0 | — |
| Santa Casa da Misericórdia de Lisboa — hastas públicas de imóveis | Active | 0 | 12 November 2026, 14:54, Lisbon time |
A source that is not active, or that does not appear in the table, is not covered. We do not claim to have every property for sale in Portugal: we have those that the active sources publish and that meet the requirements in section 5.
5. What we do with the data
- We keep the capture of the page and of the documents as they were published, in a private archive, so that we can check later what the source said.
- We remove personal data. Names and tax numbers of natural persons are taken out of the texts before any other step. See the Privacy Policy, section 10.
- We normalise. We convert each notice to a common format: type of property, areas, values, dates, type of sale, selling entity.
- We locate. We link the property to its parish, municipality and district, based on the official CAOP boundaries. We keep the degree of precision of the location: exact, at street level, or parish only.
- We remove duplicates. The same property may appear in several sources or be put up for sale again. We recognise it, in this order, by the tax register article together with the parish and unit, by the land registry description and, lastly, by similarity of address, area and number of rooms. When the similarity is not clear, a person decides.
- We record changes. We compare each check with the previous one and keep what changed: value, dates, status, documents, result.
- We publish only the notices that have, at least, a municipality, a base value, dates and a link to the official notice.
6. Statuses of a sale
| Status | Meaning |
|---|---|
| Upcoming | The sale has been announced but has not yet started |
| Open | The period for bidding or submitting proposals is open |
| Closing soon | Fewer than 48 hours remain until the end |
| Awaiting result | The period has ended and the source has not yet published the result |
| Sold | The source indicates that there was a sale |
| Not sold | The source indicates that there was no sale |
| Cancelled | The source withdrew or cancelled the sale |
| Suspended | The source indicates that the sale is suspended |
Finished sales are not deleted: they feed the history and the statistics. Twelve months after the result, history pages stop showing the address and show only the parish.
The status we show is that of the last check. A sale may be suspended or cancelled at the source before Leiloeiro records it.
7. How the artificial intelligence analysis works
We use artificial intelligence systems for four tasks: extracting data from notices of sale, writing the summary and the risk indicators, producing in-depth reports and translating into English. In every case, the result is automated information about public documents. It is not legal advice.
Data extraction. The system reads the text of the listing and of the notice of sale and fills in fields such as areas, share sold, occupancy, lease, usufruct, liens and encumbrances mentioned, use permit, state of repair, visiting arrangements and deposit.
- Every field needs textual evidence: the page and the excerpt of the document on which it is based. Without evidence, the field stays empty. The system is instructed not to infer or guess.
- Every field has a confidence level.
- Values in euros and dates are also extracted by fixed rules, without artificial intelligence. If the two methods give different results, the property page goes to review by a person.
Summary. Three to five factual sentences, each linked to the page of the notice of sale that supports it.
Risk indicators. Six dimensions: occupancy, liens and encumbrances mentioned, lease, share sold, documentation and state of the property. Each has one of four values, always with an icon, text and one line of justification:
| Value | Meaning |
|---|---|
| Green | The documents address the subject and do not mention a problem |
| Amber | The documents mention something that should be confirmed |
| Red | The documents mention a relevant limitation |
| Unknown | The documents do not address the subject, or it was not possible to read them |
The indicators describe what the documents say. They do not describe the reality of the property. A green indicator does not mean there are no problems: it means we found no reference to a problem in the documents analysed. Always confirm in the official notice of sale and, when necessary, with a lawyer or solicitor.
Review by people. A property page goes to a manual review queue when: the values or dates extracted by the two methods do not match; the system returns an invalid result after a second attempt; the identification of duplicates is uncertain; or someone reports an error. The remaining pages are published without individual review by a person.
Quality control. Before changing the instructions given to the system, we measure the results on a set of real notices of sale annotated by hand. The minimums we require are 95% accuracy on values and dates and 90% on the risk indicators. This means that a share of the pages may contain errors.
Personal data. The texts sent to the artificial intelligence systems do not include names or tax numbers of natural persons.
Translation. Content in English is translated automatically, with a fixed glossary for legal terms, reviewed by people. In case of doubt, the Portuguese text prevails and, above it, the official document.
8. Estimates and their limits
Everything that is an estimate is labelled "Estimate".
Acquisition costs. We calculate IMT (property transfer tax), Imposto do Selo (stamp duty) and registration costs from the value shown and the tables in force, whose official source we indicate in the calculator.
- The calculation assumes the most common situation. The actual tax depends on facts we do not know: the purpose the property is intended for, exemptions, your personal situation, the taxable value of the property, the final sale value.
- It does not include other possible costs, such as condominium debts, building works, the costs of vacating the property, fees or VAT, where applicable.
Comparison with INE. We compare the value per square metre with the median value of sales of family dwellings published by INE, Statistics Portugal (Instituto Nacional de Estatística), for the parish or the municipality.
- The median refers to all sales of dwellings in an area, in a past period. It is not a valuation of the property.
- It does not take into account the state, occupancy, liens or type of the property concerned.
- In areas with few sales, INE does not publish the parish value; we then use the municipality value, and we say so.
- We only compare when we know the area of the property, and only for housing.
Leiloeiro statistics. The statistics by area (sales, median discount against the base value, value per square metre) use only the notices from active sources and the results those sources publish. Not all sources publish results. With few cases in an area, the values are not very representative; for that reason, we do not publish statistics below a minimum number of cases.
9. Known limitations
- Coverage. We only show what the active sources publish. See the table in section 4.
- Delay. There is always an interval between publication at the source and the update on Leiloeiro.
- Scanned documents. Notices of sale in image form are read by character recognition, which fails more often than reading text.
- Missing documents. If the source does not publish the notice of sale, or only makes it available to registered users, the analysis is based only on the text of the listing.
- Information that is not in the documents. Actual occupancy, debts, unlawful building works or the interior state of the property are often not in the documents. The analysis cannot know them.
- Location. Some addresses do not allow an exact location. We indicate the degree of precision.
- Duplicates. There may be duplicate pages or, more rarely, pages of different properties merged by mistake.
- Results. The final value and the result only appear when the source publishes them.
10. How to report an error
On each property page there is a "Report an error" link. You can also write to the contact page, indicating the page and what is wrong.
- We check against the official notice and correct whatever is our error.
- If the error is in the official notice, we cannot correct it at its origin. We tell you which entity to contact.
- If the information concerns you as a person, use the Correction or removal request page.
This page exists in Portuguese and in English. If the two versions differ, the Portuguese version prevails.