Investors have increasingly used the instrument of withholding taxes to evade dividend taxation, employing ‘cum-ex’ transactions around ex-dividend dates. Using German stock trading data, this column provides evidence for these types of transactions, showing that there is a substantial increase in the number of stocks traded immediately before the ex-dividend date, with much stronger increases in ‘over-the-counter’ transactions, where trades are particularly easy to arrange.  Given the evidence, withholding-tax non-compliance in the form of cum-ex transactions should not be regarded as some type of financial market arbitrage exploiting a tax loophole but a form of deliberate tax fraud.