Early tax return filers have been punished rather than rewarded by the Dutch tax office, as a computer glitch meant all their information was deleted.
At least 730,000 people will now have to resubmit their 2007 tax returns.
No backups were made of the electronically-filed returns, and the only information to survive was the social security numbers of those affected.
The Dutch tax office has been struggling with IT problems since last year, when 400,000 companies had to resubmit payroll details because of a software fault.
The Auditor-General already noticed the aging IT systems at the rental and health care section earlier this year, but losing 730,000 returns is without doubt the worst hiccup in the tax office's battered IT history.
Finance Minister Jan Kees de Jager said the head tax office will be reorganised, but updating the software and IT systems will still take years.
Dutch MPs expressed anger at the snafu, but taxpayers will not be compensated, the Dutch Parliament decided this week.
However, the losses may not be as bad as feared. Most Dutch taxpayers do not have to submit their tax returns until 1 April and the early birds probably still have a copy of their electronic tax returns. ®