The ZKO posting notification in Austria: which form, which deadline, which papers on site

An employer posting or hiring out staff to Austria files an electronic notification with the Central Coordination Office at the Federal Ministry of Finance before work starts. ZKO 3 covers a posting, ZKO 4 a cross border hiring out. A copy of the notification, the A1 document and the pay records must be available at the place of work.

Which form for which case

The Central Coordination Office sits inside the fraud prevention arm of the Federal Ministry of Finance and is the point of contact for inspections under the Wage and Social Dumping Prevention Act, the LSD-BG. The family of forms is small, but picking the wrong one decides whether the notification is valid.

The difference between a posting and a hiring out is not a matter of wording. A posting means the sending company performs its own service in Austria with its own staff. A hiring out means the staff work under the direction of an Austrian user company. Reporting a hiring out as a posting is a filed but materially wrong notification, and an LSD-BG inspection treats it like a missing one.

Deadline and form: electronic, before work starts, one notification per posting

The notification is filed only through the electronic form service of the Federal Ministry of Finance. Email, fax or paper is not a notification. It must arrive before work starts, and for mobile transport workers already before entry into Austria, under section 19 paragraph 2 of the LSD-BG. Before work starts means before the first working hour at the Austrian site, not later the same day and not at the end of the first week.

One notification is due per posting, according to the ministry in 2026. If anything changes, the composition of the crew, the place of work or the duration, an amending notification must follow without delay. Without delay is a legal standard rather than a margin: the change is reported once it is settled, not at the next payroll run.

The form asks for details that should exist before you open it: the sending company and its contacts, the Austrian client or user company, the exact place of work, the start and expected end of the assignment, the activity, and the name, date of birth and social insurance data of every posted person. A missing field means the form does not submit, while the deadline keeps running.

One special case concerns employers from third countries with no seat in the European Economic Area. For them a notification is not enough; they need an authorisation, according to the ministry. Missing that point means planning an assignment on a legal basis that does not apply to your company.

What has to be available on site

Section 21 of the LSD-BG requires the documents to be kept at the place of work, meaning where the inspection happens and not at head office in the home country. Required are:

• a copy of the ZKO notification,
• the A1 social insurance document or an equivalent proof,
• the pay records in German or English.

The language requirement is where most site inspections come apart. Payslips and time records in the language of the sending company do not satisfy section 21 of the LSD-BG; they must be in German or English. That translation is a step before departure, not something supplied after the inspection.

The A1 document is the second recurring obstacle, because it comes from the social insurance institution of the sending state and takes processing time. How it is applied for and what it covers is set out in the A1 certificate for postings. How an inspection runs and what penalties the LSD-BG provides is covered in the wage dumping act inspections.

The notification itself costs nothing: the ministry's form service carries no fee. The work sits in the preparation, and it repeats with every posting. Seasonal employment in Austria follows a different regime of quotas and employment permits, described in Austria's seasonal quotas.

The ZKO notification is therefore a short form with an unforgiving deadline. Electronic, before work starts, one filing per posting, changes reported without delay, and three documents on site in a language the inspector can read. Employer duties across the other Austrian assignments are collected on the employers page.