As of 1999 Mr. Wille started to specialize in the field of pension law. Together with a fellow-partner, he formed the interdisciplinary pension group within Simmons & Simmons, which was among the first in its kind in the Netherlands.
In 2008 Mr. Wille decided to switch to the pension group of Deloitte, in order to gain a broader insight in the field of pension law. At Deloitte it was Mr. Wille's responsibility to monitor all legal aspects of Deloitte's advice to its clients in the field of pensions. The area of law in which he became active therefore remained unchanged, and comprised the pension law aspects of M&A’s, co-determination rights, equal treatment, mandatory participation in pension plans (including exemptions), amendments and harmonization of pension schemes, supervision and indexation. Moreover, Mr. Wille played an active role in the design of alternative pension solutions, e.g. in the form of a premium pension institution (PPI). Mr. Wille also set up an employment group within Deloitte.
Working closely together with his colleagues from other disciplines (tax, actuarial and audit), Mr. Wille was able to actually broaden and deepen his knowledge in the field of pensions. After almost 4 years with Deloitte, Mr. Wille felt compelled to return to private practice. Full of enthusiasm he started his own law firm, specialized in pension law.