Damages

Contributory fault and limitation: unknown wrongdoer

Unknown wrongdoer in Austria: knowledge, limitation under section 1489 ABGB, reasonable investigation and contributory fault under section 1304 ABGB.

BRANDAUER Rechtsanwälte
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Mag. Bernhard Brandauer, Rechtsanwalt

BRANDAUER Rechtsanwälte · Damages and civil law

Details decide a damages claim: cause, evidence, each head of loss and the applicable deadline. We put these levels into a clear order and represent your interests in negotiations and in court.

22 September 2026 · Mag. Bernhard Brandauer, Rechtsanwalt

When no responsible person can initially be identified after a loss, two different risks arise: identification may take time while evidence deteriorates and limitation periods continue. It is also necessary to ask whether the injured person contributed to the difficulty of clarification or to an increase in the loss.

Section 1489 ABGB generally links the three-year limitation period to knowledge of the damage and the person responsible. If that person remains unknown, the provision sets a generally thirty-year outer limit. This does not mean that securing a claim can safely be postponed.

This article explains how an unknown wrongdoer, knowledge, reasonable investigation, contributory fault under section 1304 ABGB and limitation are assessed separately in Austria.

Assess your situation

Which question about an unknown wrongdoer is open?

Separate identification, your investigation, the loss and limitation dates. This shows whether the main issue is limitation, evidence preservation or possible contributory fault.

01 Question 1

What is mainly unclear in your case?

When the responsible person is unknown, limitation, identification and evidence preservation may develop on different timelines. Separate these questions.

Result

Your orientation

01

Check knowledge dates and the outer limit

Prepare a timeline of the loss, identification and correspondence. Mark when the person became reliably known and which limitation rule may apply.

02

Organise investigation steps and evidence

Preserve original records, official contacts, video and witness details. Record when each clue became available and what it actually proves.

03

Separate personal conduct

Document available information, reasonable steps and the actual effect on the loss or its proof.

What section 1489 ABGB provides when the wrongdoer is unknown

Section 1489 ABGB generally links the three-year limitation period to knowledge of both the damage and the person responsible. If the responsible person is not known, the start of the period cannot simply be equated with the date of the loss.

The provision also sets a generally thirty-year outer limit where the damage or the person responsible has not become known. This does not answer every issue. The legal basis, type of loss, possible special rules and the steps taken to clarify the identity still require examination.

The guidance on evidence, negotiations and limitation provides a wider framework. This article focuses on the link between an unknown responsible person, reasonable investigation and possible contributory fault.

When knowledge of the wrongdoer is established

Knowledge requires more than a mere suspicion. In RS0034459, the Supreme Court stated that the mere possibility of knowing the person responsible does not replace knowledge for the purposes of section 1489 ABGB. The relevant question is whether the facts are known well enough to prepare enforcement of the claim.

After a traffic accident, the registration number, driver, keeper, insurer and witness evidence may become available at different times. In an anonymous online incident, an unclear fall location or damage caused by an unidentified device, identification may take longer. Record each step with its date and supporting record.

Later identification does not automatically resolve every further limitation issue. It must be examined which loss was already known, whether further consequences developed and whether the claim concerns the same or another person.

Which investigations are sensible when the person is unknown

If the responsible person is not known, reasonable clarification should not be postponed. Depending on the event, this may include a police report, preserving photographs and video, speaking to witnesses, asking an operator for records and documenting insurance details.

Keep a chronology: when was the loss discovered, what clues existed, when were records requested and what answer was received? Preserve unsuccessful requests as well. This shows whether identification was objectively open or whether concrete indications already existed.

For personal injury, document medical findings and the development of consequences separately. The damage documents checklist helps arrange evidence by event, cause and head of loss.

How personal conduct is assessed as contributory fault

Section 1304 ABGB concerns the injured person’s contribution to the occurrence or increase of the loss. It does not follow that incomplete investigation automatically amounts to contributory fault. Specific conduct, blameworthiness in the circumstances and an effect on the claimed loss are required.

The assessment asks what information was available, which steps were realistically possible and whether an omission actually made clarification or mitigation more difficult. A person need not take every conceivable investigative step, but recognisable evidence and reasonable reports should not be ignored without explanation.

The difficulty of pursuing a claim against an unknown person must be separated from the substantive issue of contributory fault. Lack of knowledge may concern limitation, while personal conduct may affect the amount of loss or its proof.

Which evidence matters for damage and responsibility

First preserve the original loss: photographs, invoices, medical records, repair estimates, accident reports, correspondence and witness details. Add the date, source and relevance to each item. For digital traces, retain the original file and preservation date.

Evidence about the responsible person may include official records, insurance information, keeper data, video, messages and witness statements. Mark a suspicion as a suspicion and separate it from confirmed facts. This makes knowledge under section 1489 ABGB easier to assess.

For personal injury, the guidance on personal injury and recovery costs can supplement the review. For property damage, connect repair, diminution in value and consequential costs to their cause.

How limitation periods are assessed

For the regular period under section 1489 ABGB, both the damage and the person responsible must be known. The start must therefore be established from a concrete timeline. Record not only the event but also when the responsible person became reliably identifiable.

If the person remains unknown, section 1489 ABGB generally refers to a thirty-year outer limit. This is not a reason to postpone securing the claim. Evidence can disappear, memories fade and later enforcement may become harder.

The limitation check helps record damage, knowledge, identification and correspondence. Whether proceedings or another protective step is needed depends on the circumstances and legal basis.

Why contributory fault and limitation remain separate

Contributory fault and limitation answer different questions. Section 1304 ABGB concerns allocation of a loss to which the injured person allegedly contributed. Section 1489 ABGB concerns the period in which the claim can be pursued in light of knowledge and statutory limits.

An unknown wrongdoer may mean that the start of the three-year period is not immediately clear. It does not mean that every delay in preserving evidence is harmless. Conduct in securing proof and taking reasonable clarification steps may be assessed separately.

Conversely, failure to investigate does not automatically show that the wrongdoer was already known. The actual information must be assessed from the records and chronology.

Common errors where the wrongdoer is unknown

A common error is entering the event date as the start of the three-year period without further review. The opposite assumption, that nothing needs to be done for thirty years, is equally unsafe. Neither replaces a concrete timeline.

It is also problematic to collect clues only orally or to fail to preserve video, contact details and messages promptly. If a possible wrongdoer is named, record whether this is confirmed identity or only an investigative lead.

Do not merge the questions of responsibility and loss. Identity, causation, amount, personal contribution and limitation each require their own evidence.

How to prepare the matter for legal review

Create four columns: loss event, indications of responsibility, your clarification steps and limitation dates. Add the date, document and open question for each entry. This shows which information is secured and where review must begin.

Then separate the heads of loss. For personal injury, this may include medical records, recovery costs, loss of earnings and pain and suffering. For property damage, record repair, diminution in value and necessary consequential costs separately.

For legal review, the complete chronology, original records and correspondence with authorities, insurers or possible responsible persons are particularly useful. Precise knowledge dates and investigation steps make the interaction between sections 1304 and 1489 ABGB clearer.

Practical core: Where the responsible person is unknown, record limitation dates, identification, evidence preservation and personal conduct separately. Sections 1489 and 1304 ABGB answer different questions.

Frequently asked questions

Contributory fault, unknown wrongdoer and limitation

Does the three-year limitation period also run when the wrongdoer is unknown? +
Section 1489 ABGB generally links the three-year period to knowledge of the damage and the person responsible. If the person is unknown, the start must be assessed from the actual information available.
Is suspicion enough to treat the wrongdoer as known? +
Not automatically. In RS0034459, the Supreme Court stated that the mere possibility of knowing the person responsible does not replace knowledge under section 1489 ABGB.
Must I investigate even if the person is unknown? +
Reasonable clarification and evidence-preservation steps should be documented promptly. The necessary measures depend on the event, available clues and the risk that evidence may be lost.
Can a failure to investigate amount to contributory fault? +
Not automatically. Specific blameworthy conduct and a comprehensible effect on the loss or its proof are required in the circumstances of the case.
What if the person responsible remains unknown? +
Section 1489 ABGB generally refers to a thirty-year outer limit. Claims and evidence should still be secured early because enforcement depends on further circumstances.

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