Nine years ago, a significant shift occurred in tax administration with the introduction of the "Belegvorhaltepflicht," or the obligation to retain receipts, replacing the previous "Belegvorlagepflicht," or the obligation to submit receipts. This change fundamentally altered how individuals and businesses interact with tax authorities. Effectively, taxpayers are no longer required to attach or digitally upload every receipt, such as tax certificates, cash register slips, or bank transfer confirmations, when filing their tax returns. The primary expectation is now that taxpayers simply keep these documents readily available. However, this simplification does not negate the possibility of tax officials requesting further clarification and documentation.

In specific circumstances, proactively submitting supporting evidence alongside your tax declaration can expedite the processing of your return and lead to a quicker refund. This article delves into the scenarios where providing documentation upfront is advisable, based on guidance from tax authorities and expert recommendations.

The Evolution of Tax Documentation Requirements

Historically, the submission of every single receipt was a cumbersome process for both taxpayers and tax offices. The transition to the retention obligation aimed to streamline tax filings and reduce administrative burdens. This move was part of a broader digitalization and efficiency drive within tax administrations across various jurisdictions. The underlying principle is that taxpayers should be able to substantiate their claims if audited, rather than submitting a mountain of paper with every filing.

However, tax authorities retain the right to request verification, and certain situations inherently trigger closer scrutiny. The Federal Ministry of Finance (Bundesfinanzministerium) and state tax administrations provide guidelines on when this proactive submission is beneficial. While specific lists of "trigger points" can vary slightly between federal states, the overarching principle remains consistent: demonstrate the validity of significant or potentially unusual claims.

In North Rhine-Westphalia (NRW), a notable practice previously involved the annual publication of "Prüffelder" (audit focus areas). These lists highlighted specific sectors or types of income that tax offices intended to examine more closely in a given year. The intention behind these publications was to facilitate a smoother process for both tax advisors and tax officials. Tax advisors could proactively submit relevant documentation for these identified audit areas, thereby preempting requests from tax inspectors and accelerating the review process. Although NRW no longer publishes these specific "Prüffelder," the underlying principle of anticipating potential scrutiny and providing supporting documentation for significant or complex tax matters remains relevant.

Identifying "Significant Facts" for Documentation

The concept of "significant facts" or "besonderen Sachverhalten" is central to understanding when to submit supporting documents. Tax administrations often define these as situations that deviate from the norm, involve substantial amounts, or have the potential for misinterpretation or error. These are not necessarily indicative of wrongdoing but rather areas where the tax authority might require more detailed evidence to confirm the accuracy of the tax return.

The financial administration of NRW, in alignment with guidance from other states such as Bavaria, identifies several key scenarios where submitting documentation upfront is recommended. These recommendations are designed to help taxpayers navigate potential inquiries and expedite their tax assessments.

Scenarios Warranting Proactive Documentation Submission

While the general rule is that receipts do not need to be submitted with the tax return, there are specific instances where doing so can prevent delays and potential complications. These situations often involve claims that are either new, unusually large, or fall into categories that historically attract greater attention from tax authorities.

New Provisions for Pension Contributions

For certain professional groups, specialized pension funds exist as alternatives to the statutory pension insurance. These often cater to professions like doctors, architects, lawyers, psychotherapists, and engineers. In many cases, employers of salaried employees contribute to these professional pension schemes.

For individuals making contributions to these professional pension schemes for the first time, it is advisable to submit supporting documentation. The same recommendation applies to taxpayers making voluntary contributions (additional payments) to the statutory pension insurance. Jana Bauer, managing director of the Federal Association of Wage Tax Assistance Associations (BVL), explains that currently, only regular pension contributions are electronically transmitted to the tax authorities. Therefore, any new or voluntary contributions that fall outside this standard electronic reporting may require explicit substantiation. This proactive step can help the tax office accurately assess these new or additional pension expenses, potentially leading to a more favorable tax outcome without the need for subsequent inquiries.

Significant Donations

Donations to charitable organizations can be deducted as special expenses. For amounts up to 300 Euros, a bank confirmation (such as a bank statement) or a cash deposit receipt is usually sufficient proof. For larger amounts, a donation receipt from the charitable organization is mandatory. However, for what are considered "significant donations," the tax administration of NRW recommends submitting proof along with the tax return.

The tax administration does not specify a precise monetary threshold for what constitutes a "significant donation." According to the Upper Finance Directorate of NRW, the classification of a donation as significant is "always based on the individual case." Factors such as the absolute amount of the donation and its proportion to the taxpayer’s taxable income can play a role. Submitting documentation for substantial donations upfront can help the tax office verify the charitable nature and the amount of the contribution, potentially expediting the recognition of these deductions.

Alimony Payments

Tax authorities often view alimony payments with a degree of scrutiny due to the potential for abuse. Since the tax year 2025, such payments can only be deducted if they have been transferred to a bank account. Furthermore, the tax office consistently requires proof of the recipient’s need for support.

"Typical alimony payments include situations where parents provide financial support to their children during their studies – for whom they no longer receive child benefit," explains tax expert Bauer. The condition for this deduction is that the supported child has no independent income and possesses only minimal assets. If the child earns more than 624 Euros per year, these earnings are offset against the alimony payments.

For individuals supporting recipients abroad, it is necessary to complete alimony declarations and have them confirmed by local authorities at the recipient’s place of residence. The federal tax administration provides forms in various languages for this purpose, which should be attached to the tax return. This detailed documentation is crucial for substantiating the claim and preventing potential disallowance.

Application for Unlimited Tax Liability

Individuals without a residence in Germany are generally not subject to unlimited tax liability. While this might seem advantageous initially, it can lead to significant disadvantages if the individual earns income in Germany. This is because those not subject to unlimited tax liability in Germany are not eligible for tax-free allowances, such as the basic personal allowance.

Individuals who apply for unlimited tax liability under Paragraph 1, Section 3 of the Income Tax Act (Einkommensteuergesetz) are advised by the NRW tax administration to submit supporting documents. Unlimited tax liability may be granted if an individual does not have a residence in Germany but earns at least 90 percent of their income within the country, or if their foreign income does not exceed the basic personal allowance. Providing evidence for these conditions proactively can help the tax office process the application efficiently.

Reduced Taxation of Severance Pay

Individuals who received severance pay, compensation, or remuneration for long-term services in the previous year may feel a particular urgency to file their tax return promptly. This is because, since 2025, the tax advantage for such payments is no longer considered by the employer when calculating wage tax. Instead, affected individuals must now apply for the more favorable taxation through their tax return.

The underlying principle for this favorable tax treatment is the "Fünftelregelung" (one-fifth rule). This rule treats the lump-sum payment as if it were spread over five years, effectively reducing the overall tax burden. According to the NRW tax administration, submitting documentation related to these payments is advisable. This allows the tax office to correctly apply the "Fünftelregelung" and ensure the taxpayer benefits from the intended tax relief.

Home Office Expenses

Tax authorities often scrutinize claims related to home offices. This is understandable, as the size of the room and the proportion of household costs can lead to substantial tax savings. If a home office qualifies as the primary place of work, expenses can be deducted as advertising costs without limitation. For the tax office to recognize a home office, it must not contain any private items such as a bed, wardrobe, or hobby equipment.

However, the acceptance of submitted documents for home office expenses depends on the specific tax office. Daniela Karbe-Geßler from the Federation of Taxpayers (Bund der Steuerzahler) notes that "many tax offices have their own forms for recording the home office, which taxpayers must fill out." In such cases, simply sending receipts may not suffice.

Alternatively, the home office flat rate offers a more straightforward option. For each day worked from home, employees can claim an allowance of six Euros, capped at a maximum of 1260 Euros per year. This flat rate is also accessible to those who do not have a dedicated office space but work from their kitchen table or a guest room. The choice between deducting actual expenses or using the flat rate often depends on the individual’s specific circumstances and the amount of documentation available.

First-Time Double Household Management

Tax authorities are particularly attentive when expenses appear for the first time in a tax return. This includes situations involving double household management for professional reasons. For the tax office to recognize a second residence, the commute to work must be significantly shorter from this second location. Up to 1000 Euros per month can be deducted for accommodation costs.

To substantiate these expenses, it can be beneficial to submit the rental agreement, proof of deregistration from the previous residence, and, if applicable, invoices for furnishing the second apartment with the tax return. "The plausibility is usually established by the new address of the employer and the second residence at the place of employment," states Bauer. This proactive approach can help the tax office quickly verify the legitimacy of the double household setup and the associated expenses.

Travel Expenses

Individuals claiming business-related travel expenses in their tax return are also advised by the NRW tax administration to submit supporting documents directly. In practice, employers’ confirmations of out-of-town work activities are often requested, according to Karbe-Geßler. Confirmation that the employer did not cover these costs may also be requested. Providing a detailed breakdown of travel expenses, including dates, destinations, and the purpose of the travel, along with receipts, can help expedite the process and avoid requests for further information.

First-Time Foreign Income

As soon as taxpayers earn income abroad for the first time, they should submit supporting documentation. According to the NRW tax administration, this applies to individuals who have received income from non-self-employment or pensions abroad, or have generated income that must be declared in Annex AUS ( Anlage AUS). This category also includes income from private sales transactions. Furthermore, when moving away from Germany or returning to Germany, documentation related to Annex WA-Est should be provided.

This requirement stems from the need for tax authorities to accurately assess global income and apply relevant double taxation treaties. Proactive submission of proof of foreign income and any related taxes paid can help prevent misunderstandings and ensure correct tax treatment.

Capital Asset Losses

Taxpayers should also submit documentation when reporting losses from capital assets, according to the NRW tax administration. Bank statements and tax certificates from financial institutions are suitable for this purpose. While financial institutions automatically remit capital gains tax to the tax authorities, the data from tax certificates is not always transmitted electronically. Providing these certificates allows the tax office to verify the reported losses and ensure they are correctly offset against taxable income.

Tax on Substitute Measurement Basis

In certain cases, the sale of securities may lead to taxation based on a substitute measurement basis. This can occur if the bank is unaware of the original acquisition costs of the securities, for example, if a securities depot from abroad was transferred to a German bank. In such scenarios, 30 percent of the proceeds from the sale are considered profit. Lower profits must be substantiated. If the profit was higher and the investors do not report this, they risk being accused of tax evasion. Submitting proof of the actual acquisition costs is crucial to avoid this situation and ensure correct taxation.

First-Time Rental and Leasing Activities

Similar to the rules for home offices, the specific documentation requirements for rental and leasing activities can vary among tax offices. "For those who rent out a property and claim a depreciation allowance for the first time in their tax return, it is best to submit the purchase price allocation directly," advises Karbe-Geßler.

The tax office will inquire about this in every case. This is because only the costs associated with the building itself can be tax-deductible, as the value of land generally does not depreciate. Therefore, when purchasing a property that includes land, it is advisable to have a purchase price allocation prepared by the notary at the time of the transaction. This document clearly delineates the value attributed to the building versus the land, facilitating the accurate calculation of depreciation.

Income from Cryptocurrencies

Investors in cryptocurrencies can also expect inquiries from tax authorities. The trading of Bitcoin, Ethereum, and similar digital assets is treated as a private sale transaction for tax purposes. Profits remain tax-free if the total profits from all private sale transactions in a calendar year are less than 1000 Euros. Furthermore, profits remain tax-free if the cryptocurrencies are held for longer than one year.

"If investors trade intensively with cryptocurrencies, they can quickly lose track of tax implications. Therefore, tax authorities look very closely in these cases and demand detailed statements as proof," says Karbe-Geßler. This emphasizes the importance of meticulous record-keeping for all cryptocurrency transactions, including purchase dates, prices, sale dates, and sale prices.

Child-Related Expenses

Expenses for childcare, such as for nurseries, kindergartens, or after-school care, are considered special expenses. Since 2025, parents can deduct 80 percent of a maximum of 6000 Euros per child annually – totaling 4800 Euros – as special expenses. This represents an increase of 800 Euros compared to the previous year.

For school-aged children, tuition fees for private schools are also deductible. These can be declared in Annex K (Anlage Kind). Annually, 30 percent of the school fees, up to a maximum of 5000 Euros, can be recognized as special expenses.

In both scenarios, it is recommended to submit supporting documents such as contracts and invoices, along with payment confirmations, with the tax return for the first year these expenses are claimed. This helps the tax office verify the eligibility and amount of the deduction.

Energy Efficiency Measures

Property owners who wish to improve the energy efficiency of their owner-occupied home or apartment and claim tax deductions must provide evidence. For renovation work to be tax-deductible, it is necessary to engage a specialist company that issues a formal certificate detailing the measures undertaken.

"Without this certificate, prepared according to official templates, the investment will not be recognized for tax purposes. Therefore, it must be submitted along with the tax return," states Bauer. This requirement underscores the importance of obtaining and retaining these specific certificates for any energy efficiency renovations.

Extraordinary Burden ("Außergewöhnliche Belastungen")

The list from Bavaria also mentions the first-time declaration of a disability or a change in the degree of disability (GdB) as a reason for submitting supporting documents. This will be the last time it is necessary for the 2025 tax return. Since January 1, 2026, the GdB will be automatically transmitted electronically from the responsible authority (Versorgungsamt) to the tax office for new determinations or changes. This streamlining aims to reduce the administrative burden on taxpayers for this specific item.

Conclusion: Proactive Documentation as a Strategy

In summary, while the general trend in tax administration is towards reduced submission requirements, understanding the exceptions and specific scenarios where providing documentation is beneficial is crucial. By proactively submitting relevant proof for "significant facts" or in situations involving new or substantial claims, taxpayers can not only expedite the processing of their tax returns but also minimize the risk of prolonged inquiries and potential disputes with tax authorities. This approach fosters transparency and can lead to a more efficient and favorable tax assessment process.

This article was originally published in March 2025. It was reviewed and updated on July 9, 2026.