Allart Haasjes has a broad banking and securities law practice. He specialises in representing financial institutions and regulatory bodies in complex civil liability suits. For example, he has defended such entities against claims based on the violation of a bank's duty of care and claims of failed supervision. Allart also regularly represents banks in disputes regarding the rights of individuals under Dutch privacy legislation to inspect their personal data. He appears before district courts, appellate courts and the Netherlands Supreme Court, as well as before extra-judicial dispute settlement bodies. In addition, Allart advises on a wide range of issues in the banking and securities field, such as issues arising under the Dutch financial supervision laws or in relation to payment transactions, set-off, netting and attachments. He also has substantial knowledge and experience of Antillean and Aruban banking and securities law.

Allart obtained a degree in business law and criminal law from the University of Groningen in 2002, and joined NautaDutilh in that same year. He is a member of the Dutch Securities Law Association..