Beilage L 1k (2025) — Child Supplement to the Austrian Tax Return

What is L 1k (2025) — child supplement to the tax return?

The Beilage L 1k is a supplement published by Austria's Federal Ministry of Finance (Bundesministerium für Finanzen, BMF). You attach it to your annual employee tax assessment, the Arbeitnehmerveranlagung on form L 1, or to your income tax return on form E 1. The L 1 or E 1 is about you; the L 1k is about one child. If you claim for three children, you fill in three copies. The edition covered here is L 1k-PDF-2025, Version vom 25.04.2025, for the 2025 tax year.

The L 1k is where you claim the Familienbonus Plus, Austria's tax credit for children, and decide whether you take half or the whole of it. It also carries the maintenance deduction (Unterhaltsabsetzbetrag) for a child who doesn't live with you, extraordinary expenses (außergewöhnliche Belastungen) such as medical costs, training away from home or a child's disability, and the rare case where an employer's childcare subsidy has to be taxed after the event. The form itself says the Familienbonus Plus must be claimed on every assessment, even if your employer already applied it through payroll, or you risk an unwanted back-payment.

FileIt explains every box of the L 1k in English, with the original German terms alongside, and prints your answers into the official BMF PDF, formatted the way the form's own boxes expect: amounts right-aligned with a decimal comma, dates as DDMMYYYY and names in capitals. The child's name and date of birth can be pre-filled from the People records in your FileIt vault, and the finished PDF is saved in the child's folder. FileIt does not send anything to the tax office: you print, sign and post the L 1k yourself with your L 1 or E 1, or you make the same claim online in FinanzOnline.

Who needs to fill out L 1k (2025) — child supplement to the tax return?

• Parents who receive the family allowance (Familienbeihilfe) for a child and want the Familienbonus Plus applied in their tax assessment.
• A parent whose spouse or partner receives the family allowance and who claims half or the whole Familienbonus Plus for the same child.
• Separated parents where maintenance (Alimente) was paid in full for the whole of 2025, whether you received it or paid it.
• Parents who pay legal maintenance for a child who doesn't live in their household and want the maintenance deduction.
• Parents claiming extraordinary expenses for a child, such as medical costs, a lump sum for training away from home, or costs connected with a child's disability.
• Employees whose employer's childcare subsidy was wrongly left tax-free in payroll and now has to be taxed.

When to use L 1k (2025) — child supplement to the tax return

• When you file your employee tax assessment (L 1) or income tax return (E 1) for 2025 on paper: attach one L 1k per child.
• Every year you claim the Familienbonus Plus, even if your employer already took it into account through payroll. The form warns that otherwise you may face an unwanted back-payment.
• When your family situation was the same for the whole of 2025. For special cases, such as changes during the year, the BMF has a separate form, L 1k-bF.
• When you want a different split of the Familienbonus Plus from the one your employer used in payroll; the form says you may claim a different split.

What you need before you start

• Your 10-digit Austrian social security number from your e-card, or your date of birth if you don't have one.
• Your tax number (Steuernummer) only if the L 1k goes with an E 1; with an L 1 the form says it isn't needed.
• The child's full name and 10-digit social security number, or date of birth (and a European Health Insurance Card number if the child is insured elsewhere).
• The child's country of residence, as the international car registration code (A for Austria, D for Germany and so on).
• Whether you or your partner received the family allowance, and whether maintenance was paid for the child in 2025.
• An agreement with the other parent on who claims half or the whole Familienbonus Plus.
• For the maintenance deduction: the total maintenance paid in 2025 and the monthly maintenance obligation.
• For extraordinary expenses: your costs after refunds, the share of costs you carry, the degree of disability from the official assessment, and any care allowance received.
• Your filled-in L 1 or E 1 for 2025, which the L 1k is attached to.

What’s on L 1k (2025) — child supplement to the tax return

The 2025 edition has 3 pages. FileIt asks for it in 7 parts:

1. 1. About you (Angaben zur*zum Antragsteller*in)Applicant (antragsteller*in)
2. 2. About the child (Angaben zum Kind)Applicant (antragsteller*in)
3. 3. Familienbonus PlusApplicant (antragsteller*in)
4. 4. Maintenance deduction and maintenance payments (Unterhaltsabsetzbetrag und Unterhaltsleistungen)Applicant (antragsteller*in)
5. 5. Extraordinary expenses for the child (Außergewöhnliche Belastungen für das Kind)Applicant (antragsteller*in)
6. 6. Taxing an employer's childcare subsidy after the fact (Nachversteuerung des Arbeitgeber*innenzuschusses für Kinderbetreuung)Applicant (antragsteller*in)
7. Declaration and signature (Richtigkeits- und Vollständigkeitserklärung)Applicant (antragsteller*in)

How to fill out L 1k (2025) — child supplement to the tax return, step by step

1 1. Angaben zur*zum Antragsteller*in (about you)

Give your 10-digit social security number as printed on your e-card. If you don't have an Austrian social security number, your date of birth is mandatory instead. The tax number box is only needed when the L 1k is attached to an income tax return (E 1).

The L 1k doesn't ask for your name, because it belongs to the L 1 or E 1 that carries it. FileIt repeats your numbers in the header of page 2, as the BMF form does, so the pages stay together.

2 2. Angaben zum Kind (about the child)

Enter the child's surname and first name (printed in capitals), the child's 10-digit social security number and, if there is no Austrian number, the date of birth and the identification number from the child's European Health Insurance Card. Finally give the child's country of residence as a car nationality code: A for Austria, D for Germany, H for Hungary, SK for Slovakia, SLO for Slovenia.

Remember the form's rule: one L 1k per child.

3 3. Familienbonus Plus

Choose the line that fits and whether you claim half (halben) or the whole (ganzen) bonus. Use 3.1 if no maintenance had to be paid for the child, for example parents living together, or if maintenance was owed but nothing was paid in 2025. Use 3.2 if maintenance was owed and paid in full for all of 2025, either as the parent who received the family allowance and the maintenance, or as the parent who paid it.

The bonus can be claimed in full only once per child and reduces income tax to zero at most. If more than the whole bonus is claimed for one child, each claimant is given half, which is why the form tells you to agree with the other parent first. If you paid the maintenance, part 4.1 must also be filled in.

4 4. Unterhaltsabsetzbetrag und Unterhaltsleistungen (maintenance)

4.1 is the maintenance deduction for a child who doesn't live in your household and for whom you paid the legal maintenance. Always fill in both amounts: the total maintenance you paid in 2025 and the monthly maintenance obligation. If the monthly obligation changed during the year, enter the average.

4.2 covers maintenance for a child living permanently outside the EU, Switzerland, Norway, Liechtenstein and Iceland, for whom no maintenance deduction is due. Give the total and the months of 2025 it covers.

5 5. Außergewöhnliche Belastungen für das Kind (extraordinary expenses)

This part applies only to a child for whom you or your partner received the family allowance for at least 7 months of the year, or for whom you are due the maintenance deduction for at least 7 months. The lump sum for training away from home (5.3) is the exception. 5.1 is for costs such as medical bills for a child without a disability, after refunds. 5.2 asks what percentage of the costs in 5.3 and 5.4 you carry yourself.

5.3 is the lump sum for vocational training away from home: the number of months, and the postcode and country of the place of training.

5.4 covers a child's disability. You can claim the lump-sum disability allowance with the degree of disability (at least 25%), diet allowances, or, for a severely disabled child with increased family allowance, the monthly lump sum printed on the 2025 edition (262 euros). You can also report a care allowance, school fees for a special school or sheltered workshop, and irregular costs of aids and treatment, or claim actual costs instead of the lump sums. The form spells out which items can't be combined, and FileIt checks those rules for you.

6 6. Nachversteuerung des Arbeitgeber*innenzuschusses für Kinderbetreuung

Only if your employer paid a childcare subsidy that was wrongly left tax-free in payroll. Enter the amount that has to be taxed now. Most people leave this part empty.

7 Declaration and signature (Richtigkeits- und Vollständigkeitserklärung)

By signing you confirm that everything is true and complete. The form notes that incorrect or incomplete information is an offence. If a tax adviser represents you, give their name, address and phone number in the box provided. FileIt prints the date; you sign beside it by hand.

Common mistakes to avoid

• Skipping part 3 because your employer already applies the Familienbonus Plus. The form says to claim it on every assessment anyway.
• Both parents claiming the whole bonus for the same child. Agree on the split first, or each of you ends up with half.
• Filling in one L 1k for several children. You need a separate copy for each child.
• Choosing 'I paid the full maintenance' in 3.2 without filling in part 4.1. The form requires it.
• Giving only one of the two amounts in 4.1. Both the annual total and the monthly obligation are needed.
• Combining the disability lump sums with actual costs. 5.4.1, 5.4.2 and 5.4.3 exclude 5.4.7, and 5.4.7 excludes 5.4.5 and 5.4.6.
• Sending receipts with the form. The BMF asks you not to; keep originals for at least 7 years instead.
• Using the L 1k when your family situation changed during 2025. The form points to L 1k-bF for special cases.

After you fill it out

Print the L 1k from FileIt, sign it by hand and put it with your signed L 1 (employee tax assessment) or E 1 (income tax return) for 2025, one L 1k per child. The address printed on the form is Finanzamt Österreich, Postfach 260, 1000 Wien. If you prefer, the same claims can be made online in FinanzOnline, which the form itself recommends as a paperless option.

Don't attach receipts or evidence. The form asks you to keep your original documents and receipts for at least seven years in case the tax office wants to check them. A copy of the filled L 1k stays in the child's folder in your FileIt vault, next to the other paperwork for that year.

Next year you will need a new L 1k, because the form is tied to its tax year. If your family situation changes, for example a separation or a new maintenance arrangement, check which form applies before you file.

L 1k (2025) — child supplement to the tax return: frequently asked questions

Official sources

• Blank form (PDF), published by Bundesministerium für Finanzen (BMF) — Finanzamt Österreich: https://formulare.bmf.gv.at/service/formulare/inter-Steuern/pdfs/2025/L1k.pdf?open=download
• Official instructions and guidance: https://formulare.bmf.gv.at/service/formulare/inter-Steuern/L1k.html
• Edition shown on this page: L 1k-PDF-2025, Version vom 25.04.2025 (checked 2026-09-26).

FileIt is not affiliated with or endorsed by Bundesministerium für Finanzen (BMF) — Finanzamt Österreich or any government. This page explains the form in general terms and is not legal, tax or immigration advice. Always read the official instructions, and check that you are using the edition the recipient accepts. Page last reviewed 2026-09-26.

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