One of the Magic 20 law firms has come out with a handy PDF file to help taxpayers all over the globe to come to terms with the US Internal Revenue Service and/or their own tax authorities. The document also serves as a good guide to the voluntary disclosure programmes of various countries.

In Australia, for example, taxpayers are subject to penalties for failing to disclose amounts in their tax returns, whether this omission is accidental or otherwise. The base penalty amount varies from 25% to 75% of the shortfall amount depending on the conduct of the taxpayer. The base penalty amount can be further increased or reduced depending
on the taxpayer’s conduct.

As of 1 January 2014, meanwhile, there is no longer a specific voluntary disclosure procedure in Belgium. As of 5 December 2014, Chinese laws and regulations do not establish a specific regime for the voluntary disclosure of undeclared assets or income. In Denmark, late payment is not a criminal offence but wilful misinformation can lead to 8 years in gaol. A French circular dated 21 June 2013 (modified on 12 December 2013) provides an official voluntary disclosure procedure regarding undeclared funds held abroad. Taxes due within the periods that are not barred by the statutes of limitation (i.e. at least three years and up to ten years for income taxes, wealth tax, inheritance and gift taxes in certain circumstances) can be neither avoided or reduced.) Uruguay has not enacted legislation to grant tax amnesties but, in the face of a spontaneous or voluntary declaration of non-declared income, the tax authorities are super-flexible.

The so-called 'handbook' can be found here: http://f.datasrvr.com/fr1/115/49312/Voluntary_Disclosure_Handbook_24Mar2015.pdf