The point at which tax law, criminal law and criminal tax law meet is a regular source of dangerous misconceptions in practice. Two entirely different systems of time limits run side by side and touch each other only through a handful of statutory hinge provisions.
The limitation period for tax assessment (Festsetzungsverjährung) answers the question of how long the tax office may still assess or amend a tax. The limitation period for criminal prosecution (Verfolgungsverjährung) answers the question of how long tax evasion can still be investigated, charged and tried. Each clock runs by its own rules for commencement, suspension and interruption, and the two can stop at very different times. Anyone who confuses these periods quickly miscalculates by years. The general principles of limitation in criminal law are set out separately under “Statute of limitations in criminal law”. Criminal tax law is governed by special rules that are longer, harsher and considerably less intuitive.
For completeness, two further periods must be mentioned that should not be confused with the two main clocks. The limitation period for payment under Section 228 of the German Fiscal Code (Abgabenordnung, AO) determines how long a tax that has already been assessed can still be collected, in principle five years, in the cases of Sections 370, 373 and 374 AO ten years, and under Section 230 (2) AO it does not expire as long as the assessment period is still open. The limitation period for enforcement under Section 79 of the German Criminal Code (Strafgesetzbuch, StGB), finally, concerns only the enforcement of a sentence that has already become final.
Added to this is the legislative history of what is now often called the “Lex Cum-Ex”. Until 24 December 2008 there was no separate limitation period for particularly serious tax evasion. From 25 December 2008, a ten-year period applied in what were then the standard-example cases of Section 370 (3) sentence 2 AO, and it applied to all limitation periods that had not yet expired when the amendment entered into force (Article 97 Section 23 of the Introductory Act to the Fiscal Code (EGAO); Federal Court of Justice (BGH), order of 5 March 2013 – 1 StR 73/13). Since 25 June 2017 this special period has also covered what is now number 6 of Section 370 (3) sentence 2 AO. With effect from 1 July 2020, the Second Coronavirus Tax Relief Act raised the maximum period after interruptions to two and a half times the statutory period and inserted the reference to Section 78b (4) StGB. Since 29 December 2020 the period has been fifteen years (Article 27 no. 29 of the Annual Tax Act 2020; legislative materials in Bundestag printed paper 19/25160). This extension, too, applies only to offenses that were not yet time-barred on that date. The BGH expressly confirmed this in 2025 and at the same time made clear that limitation questions are in principle to be judged according to the law in force at the time of the decision, but that periods which have already expired do not revive (BGH, judgment of 14 October 2025 – 1 StR 445/24, para. 17; BGH, order of 18 March 2024 – 5 StR 12/23, para. 91). For older cases it is therefore always necessary to check which version of Section 376 AO applied on each individual amendment date and whether the offense was still prosecutable at that time.
How long may the tax office claim evaded taxes?
The starting point is Section 169 (2) sentence 2 AO. Under this provision the assessment period is ten years insofar as a tax has been evaded and five years insofar as it has been recklessly understated. The ordinary period is four years. The ten-year period, however, is not triggered by mere suspicion. The Federal Fiscal Court (BFH) requires robust findings on the elements of tax evasion and has made clear that the tax court must establish the objective and subjective elements of tax evasion with a probability bordering on certainty, and that the burden of proof lies with the tax office (BFH, judgment of 9 April 2025 – II R 39/21).
Where tax evasion is established, the ordinary assessment period is already a full ten years. If suspensions of expiry under Section 171 AO are added, for instance through a field audit begun in time, investigations by the tax investigation office or a voluntary disclosure filed before expiry, the tax office can reopen the case well beyond a decade. And as long as criminal prosecution is still possible, Section 171 (7) AO keeps the tax period open. Open for tax purposes, however, does not automatically mean open for criminal purposes. It can therefore happen that criminal limitation has already occurred while, for tax purposes, claims can still be raised, assessments amended and disputes fought for years because the tax period started later or is held open by other suspensions.
When does the assessment period begin?
Under Section 170 (1) AO the assessment period begins at the end of the calendar year in which the tax arose. For most practical cases, however, Section 170 (2) sentence 1 no. 1 AO is the real pivot. Where a tax return, tax declaration or notification has to be filed, the period begins only at the end of the calendar year in which the return is filed, and at the latest at the end of the third calendar year following the year in which the tax arose. For classic assessed taxes such as income tax, corporation tax and trade tax this is the usual starting point of the assessment period. Section 170 AO also contains further special rules, for example for inheritance and gift tax and for certain foreign situations, which are addressed below.
The question of the period is therefore not answered by the year of origin alone. What matters is whether a filing obligation existed, when the return was filed and whether it was filed at all. Where an income tax return was wrongfully not filed, the period does not begin to float freely at some point but according to the statutory deferral of commencement in Section 170 (2) AO. A rule of thumb such as “after ten years everything is time-barred” is therefore misleading.
Inheritance and gift tax – the “eternal” limitation period
Inheritance and gift tax are subject to the special rule in Section 170 (5) AO. Under this provision the assessment period for an acquisition on death does not begin before the end of the calendar year in which the acquirer became aware of the acquisition, and for a gift not before the end of the calendar year in which the donor died or the tax authority became aware of the completed gift. The general rules of subsections 1 and 2 continue to apply alongside; Section 170 (5) AO merely sets an additional floor. In gift tax cases in particular, the clock can therefore start very late.
For inheritance cases the BFH clarified in 2025 that the acquisition that has legally taken effect is decisive for awareness of the acquisition (BFH, judgment of 4 June 2025 – II R 28/22). Anyone who assumes intestate succession for decades and only later learns from a will that has come to light that the acquisition rests on a different legal basis does not start the period for that legal basis with the first family rumour. In the case decided, the decisive moment was the probate court’s decision on the validity of the will in the certificate-of-inheritance proceedings, because another potential heir had opposed the issue of the certificate; the BFH expressly did not require that decision to have become final. The BFH thus ties the period to a secured acquisition, not to half-knowledge at the kitchen table, but it does not demand the last word from the appellate courts either.
For gifts the case law is stricter still. The BFH requires positive knowledge on the part of the competent tax office of the completed gift; in the case of an indirect gift, such knowledge exists only when the authority knows all the circumstances that constitute the gift, and mere indications that call for further inquiries are not enough (BFH, judgment of 8 March 2017 – II R 2/15). Where several assets are gifted at the same time, partial knowledge is equally insufficient. If the tax office knows only of the gift of one of these assets, the assessment period for the remaining assets does not begin to run (BFH, judgment of 26 July 2017 – II R 21/16). A notarised gift is therefore not automatically protected by limitation. Notarisation and the notary’s notification do not by themselves prove that the tax office knew of all further gifts; what matters is the content and scope of the specific notification.
In practice it is also important to distinguish between notification and tax return. In inheritance and gift tax matters the process often begins not with the formal tax return but with the notification of the acquisition under Section 30 of the Inheritance and Gift Tax Act (ErbStG). For the criminal completion of an offense committed by failing to notify, the BGH looks to when gift tax would at the earliest have been assessed and notified had the gift been reported in time. In the case decided, this produced a completion date four months after each gift, namely the three-month notification period running from knowledge plus a further one-month period the tax office could have set for filing the return (BGH, order of 25 July 2011 – 1 StR 631/10, paras. 41 et seq.). That is the criminal clock. The tax clock of Section 170 (5) AO, by contrast, can start much later, which is precisely why the two systems visibly diverge in gift tax cases.
Which events suspend the tax period?
The key provision is Section 171 AO. If a field audit is begun before the assessment period expires, the period for the taxes covered by the audit does not, under Section 171 (4) AO, expire before the tax assessments to be issued on the basis of the audit have become incontestable, not merely issued, but incontestable. This does not apply if the audit is interrupted immediately after it begins for more than six months for reasons attributable to the tax authority. New is a time cap. The suspension ends at the latest five years after the end of the calendar year in which the audit order was notified, subject to exceptions, for instance where the start is postponed at the taxpayer’s request, where international administrative assistance is used or where criminal proceedings are initiated. Under Article 97 Section 37 EGAO this five-year cap in principle applies only to taxes that arose after 31 December 2024. For earlier years it does not apply merely because the audit order was notified from 2025 onwards. For investigations by the tax investigation office, Section 171 (5) AO provides a corresponding suspension. Section 171 (7) AO builds the bridge to criminal law. In the cases of Section 169 (2) sentence 2 AO, the assessment period does not end before prosecution of the tax offense is time-barred. The calculation “always ten years for tax, perhaps already over for criminal law” is therefore often too simple.
A voluntary disclosure, too, changes the tax position and not only the criminal one. Section 171 (9) AO provides that, where a notification under Sections 153, 371 or 378 (3) AO is filed before the period expires, the assessment period does not end before one year after receipt of the notification. Anyone who believes that a late disclosure is at least ineffective for tax purposes may be overlooking a suspension that works in the tax authority’s favor.
For basic assessments (Grundlagenbescheide), for instance separate and uniform determinations for partnerships, Section 171 (10) AO applies in addition. Insofar as the basic assessment is binding for the tax assessment, the assessment period for the consequential assessment does not end before two years after notification of the basic assessment. This can considerably extend the periods for the consequential assessments concerned.
When does tax evasion become time-barred under criminal law?
The general starting point in criminal law is Section 78 (3) no. 4 StGB. Under this provision the limitation period for ordinary tax evasion is in principle five years. For particularly serious tax evasion, Section 376 (1) AO raises the period to fifteen years and expressly provides that Section 78b (4) StGB applies accordingly. Only the statutory standard examples in Section 370 (3) sentence 2 nos. 1 to 6 AO are covered; particularly serious cases not listed in the statute do not trigger the fifteen-year period. What matters here is solely whether a standard example is objectively fulfilled. The question is whether a standard example has been realised, not whether the offense appears particularly serious after the required overall assessment of the individual case, nor whether the court actually draws the sentence from the increased sentencing range (BGH, order of 5 March 2013 – 1 StR 73/13; BGH, judgment of 14 October 2025 – 1 StR 445/24, para. 28).
For the standard example of evasion “on a large scale”, the threshold remains an evaded amount exceeding EUR 50,000 (BGH, judgment of 27 October 2015 – 1 StR 373/15). If neither the standard example of evasion on a large scale nor any other standard example covered by Section 376 (1) AO is fulfilled, the limitation period is in principle five years (BGH, judgment of 24 January 2024 – 1 StR 218/23). In 2025, however, the BGH developed a separate threshold for one specific determination scenario. In the case of incorrect returns for the separate and uniform determination of income, evasion on a large scale exists where the income attributable to a group of persons is determined in favor of the participants at least EUR 140,000 away from the income actually earned (BGH, judgment of 14 October 2025 – 1 StR 445/24). This figure refers to the determined income, not to the amount of tax, and cannot be transferred to other categories of cases.
Income tax and other assessed taxes
Section 78a StGB provides that the criminal limitation period begins as soon as the offense is completed. Where an incorrect income tax return is filed, the criminal period regularly begins with the incorrect assessment. Evasion of income tax is completed upon notification of the income tax assessment in which the tax was set too low (BGH, order of 28 July 2015 – 1 StR 602/14, para. 18). Notification includes the statutory presumption of receipt in Section 122 (2) AO. For administrative acts posted after 31 December 2024, a written administrative act sent by post within Germany is deemed notified on the fourth day after posting, and one month after posting where it is sent abroad. These are calendar days, not working days. If the fourth day falls on a Saturday, Sunday or public holiday, notification shifts under Section 108 (3) AO to the next working day. The presumption does not apply if the assessment was not received at all or was received later; in case of doubt the authority must prove receipt. For assessments posted within Germany before 1 January 2025, the former three-day rule remains applicable; so the traditional talk of the “three-day fiction” no longer fits today’s law.
Anyone who files no return at all regularly pushes the completion date back. In the case of evasion by omission, the criminal limitation period for assessed taxes begins only when the competent tax office has generally concluded the assessment work in the district concerned for the relevant period (BGH, order of 7 November 2001 – 5 StR 395/01). From a limitation perspective, not filing a return is therefore often the worse idea, even though in practice it is still misunderstood as a tactical holding position.
Self-assessed taxes
In refund and remuneration cases the result of the offense depends on the tax office’s consent. Where an annual return is not filed, what matters is the complete expiry of the filing deadline. Evasion of value added tax by failing to file the annual return is completed only when the filing deadline has fully elapsed, not already during the course of its last day (BGH, order of 31 May 2011 – 1 StR 189/11). For VAT advance returns and their relationship to the annual return, the case law has developed lines of its own. Wage tax, in turn, follows its own rules; in any event it must not simply be equated with the employee’s income tax assessment.
Separate and uniform determinations
A hot spot of its own is the incorrect determination return for partnerships. In 2025 the BGH confirmed and refined its position. Where the income tax of all or individual participants is assessed only after the determination notice has been issued, the offense is completed only with the last income tax assessment for which the determination notice has binding effect; the determination notice itself then merely brings about consummation. Where, by contrast, the income tax assessments of all participants were issued before the determination notice, consummation and completion in principle coincide with the determination notice. If the incorrect determination notice leads to an amended assessment in which income tax is set lower than before, that amended assessment is decisive. What counts in each case is therefore the last tax assessment in which the incorrect determination return works in the taxpayer’s favor (BGH, judgment of 14 October 2025 – 1 StR 445/24, paras. 31 to 33). Anyone who in such constellations looks only at the determination notice calculates too short or too long depending on the sequence of assessments. Here, the precise chronology of the assessments is everything.
Inherited tax debts and one’s own duty to correct
In an estate, matters can be prolonged once more. On Section 171 (7) AO the BFH has held that the assessment period does not expire where the heir, as universal successor, steps into a ten-year assessment period and commits his or her own tax evasion by omission in respect of the same tax, for instance by wrongfully failing to make a correction under Section 153 AO. In that case the suspension continues as long as the heir can be criminally prosecuted for his or her own evasion. A further extension of the assessment period by another ten years, however, is not triggered by the heir’s own offense (BFH, judgment of 21 June 2022 – VIII R 26/19). In other words, the deceased’s old case can become a new one for the heir, and that applies to every inherited type of tax, not only inheritance tax.
Foreign accounts and crypto assets
There is no uniform special limitation period merely because assets are held abroad or in crypto assets. Here, too, limitation depends on the type of tax concerned, the time of completion of the offense and the assessment situation (Section 78a StGB, Sections 169 and 170 AO). For tax purposes, however, there are two special deferrals of commencement. Under Section 170 (6) AO, the assessment period for tax on investment income from states outside the EU and EFTA that is not automatically reported begins at the earliest at the end of the calendar year in which the income became known to the tax authority, but at the latest ten years after the end of the year in which the tax arose. Section 170 (7) AO provides the same for income connected with controlled third-country companies. Whether and how these rules apply to crypto assets depends on the classification of the income in question in the individual case; a blanket equation with investment income is not permissible.
In practice, particular risks arise here. In foreign and digital transactions, documentation, proof and subsequent clarification of the facts are often considerably more difficult. That does not make the calculation of the period easier, only the consequences of an error more expensive. Under the Crypto Asset Tax Transparency Act (Kryptowerte-Steuertransparenz-Gesetz, KStTG), which entered into force on 24 December 2025 and implements the EU directive DAC8, crypto asset service providers subject to the reporting obligation must report the information required by law to the Federal Central Tax Office for the first time for the calendar year 2026. Under Sections 9, 10 and 21 KStTG, the first regular annual report must be submitted by 31 July 2027. The direction is unmistakable: foreign structures and digital assets will become considerably more transparent for the investigating authorities in the coming years than they have been so far.
Why criminal limitation can take a very long time
Anyone who reckons with fifteen years has not finished calculating. Under Section 376 (3) AO, limitation in the serious cases occurs at the latest when two and a half times the statutory limitation period has elapsed since completion of the offense. With fifteen years, that arithmetically produces 37.5 years, and thereby expressly departs from the double period provided for in Section 78c (3) sentence 2 StGB. Before that point, limitation can be interrupted any number of times, in criminal tax law under Section 376 (2) AO additionally by notification of the initiation of administrative fine proceedings.
But even 37.5 years is no guarantee, because this maximum period covers only interruptions. Suspension (Ruhen) of limitation remains unaffected (Section 78c (3) sentence 3 StGB). Under Section 78b (4) StGB, to which Section 376 (1) AO expressly refers, limitation is suspended from the opening of the main proceedings before the Regional Court for a maximum of five years. If this ground of suspension alone applies, up to 42.5 years lie between completion of the offense and the first-instance judgment of the Regional Court. That is an arithmetical constellation, not a general absolute ceiling. Further grounds of suspension can be added, for instance suspension while criminal proceedings are stayed pending the conclusion of the tax proceedings under Section 396 (3) AO, or suspension following a formal extradition request under Section 78b (5) StGB. And if a first-instance judgment has been delivered before the period expires, limitation under Section 78b (3) StGB in any event does not occur before the proceedings have been finally concluded. Anyone calculating a limitation period must therefore reconstruct every interruption and every suspension from the file, offense by offense and person by person.
Voluntary disclosure – ten years or fifteen?
Anyone considering a voluntary disclosure (Selbstanzeige) should begin not with the calendar but with the statute. Section 371 (1) sentence 2 AO requires the disclosure to cover all tax offenses of one type of tax that are not yet time-barred, and at a minimum all tax offenses of that type of tax within the last ten calendar years. The ten-year figure is therefore not a safe cap but a minimum range. Since the reform of voluntary disclosure with effect from 1 January 2015, completeness has been the real touchstone.
Where, because of a standard example under Section 370 (3) sentence 2 AO, a fifteen-year limitation period under Section 376 AO comes into consideration, the voluntary disclosure must cover the entire period that is not time-barred. The wording of Section 371 (1) sentence 2 AO, all tax offenses of one type of tax not yet time-barred, is clear on this point. Because of interruptions or suspensions, the period not yet time-barred can even exceed fifteen years. A voluntary disclosure that simply omits offenses from years eleven to fifteen that are not yet time-barred may fail the required completeness for the type of tax concerned; in that case no immunity arises, but the evidence is already in the authorities’ hands. A special rule applies under Section 371 (2a) AO only to VAT advance returns and wage tax returns, for which a partial disclosure continues to be effective to the extent of the correction. Anyone who discloses too narrowly therefore risks losing immunity and hands the tax office the structure of the case free of charge.
Completeness alone, moreover, is not enough. Where Section 371 (3) AO requires payment, the taxes evaded for the benefit of the participant and the interest specified by law must be paid within the deadline set. Under Section 371 (2) AO, immunity does not arise where a ground of exclusion exists. In the serious cases in particular, that is the rule. Where the evaded amount exceeds EUR 25,000 per offense or where a standard example under Section 370 (3) sentence 2 nos. 2 to 6 AO applies, there is no longer any immunity under Section 371 AO. Prosecution may be avoided under Section 398a AO only where immunity is excluded solely by the grounds in Section 371 (2) sentence 1 no. 3 or 4 AO. This requires payment within the deadline of the taxes evaded for the benefit of the participant and the interest specified by law, together with an additional sum of 10, 15 or 20 per cent of the evaded tax depending on the amount evaded. Anyone who speaks of a voluntary disclosure “granting immunity” in such a constellation therefore means something other than the statute.
The no man’s land between criminal law and tax law
The legally most delicate zone begins where criminal limitation has already expired but, for tax purposes, there is no peace yet. As long as prosecution of the tax offense is not time-barred, Section 171 (7) AO keeps the assessment period open. Once criminal limitation has occurred, that bridge ends, but the tax period may still be open because of its own later commencement or other suspensions. In parallel, the instruments of the tax procedure remain available. Section 93 AO requires information to be provided where it is necessary to establish facts relevant to taxation (BFH, judgment of 30 March 2011 – I R 75/10). Anyone who in this phase simply refuses all cooperation often merely produces the basis for an estimate under Section 162 AO. The no man’s land is therefore not a lawless space but a very active one for tax purposes.
The fact that criminal limitation has occurred does not silence the tax procedure. But neither is it a licence for unlimited compelled self-incrimination. The scope and limits of the duties to cooperate depend on the specific stage of the proceedings and in particular on Section 393 AO. The precise line, above all the tension between the tax law duty to provide information and the prohibition of self-incrimination, cannot seriously be settled in a single abstract sentence; it has to be examined in the specific proceedings and fought out case by case.
This zone also includes Section 153 AO. The provision is not a patch for returns whose incorrectness the taxpayer knew for certain from the outset. It applies where a taxpayer subsequently, and before the assessment period expires, recognizes that a return is incorrect or incomplete. Subsequent recognition does not require initial good faith. The BGH has held that the duty to correct also applies to a person who did not know that the information was incorrect when filing the return but accepted that possibility, and who later comes to know for certain that it was incorrect. Anyone who intentionally fails to fulfill this duty to correct commits tax evasion by omission under Section 370 (1) no. 2 AO (BGH, order of 17 March 2009 – 1 StR 479/08). The reflexive “we’ll file something later” is therefore not a viable defense strategy.
Practical implications
Three points are decisive when assessing an individual case.
The duration of criminal limitation in the serious cases follows from the interplay of Section 376 (3) AO with the suspension provisions of Section 78b StGB and Section 396 (3) AO. The much-quoted figure of 42.5 years describes only the constellation in which suspension under Section 78b (4) StGB alone applies. The doctrinal direction is clear, but no fixed ceiling for all cases can be derived from it. Every concrete calculation remains an individual examination on the basis of the complete procedural history.
As to whether an effective voluntary disclosure in cases under Section 376 AO must necessarily also cover years eleven to fifteen, the wording and system of Section 371 (1) sentence 2 AO clearly point to the entire period not yet time-barred. For practice this changes nothing about the recommendation to disclose the entire period not yet time-barred and to clarify before filing whether immunity is achievable at all or only a decision to refrain from prosecution under Section 398a AO.
The “no man’s land” between criminal and tax limitation, finally, remains procedurally restless terrain. The statement that the tax procedure in principle remains operational is sound. The precise line in the individual case, above all in the light of Section 393 AO and the nemo tenetur principle, can only be gauged in the specific proceedings. Anyone who operates in this zone without legal counsel risks errors that can no longer be corrected afterwards.
As of September 2026 · Dr. Tobias Rudolph, Rechtsanwalt, certified specialist in criminal law and in tax law · Nuremberg, Germany