An unbounded gift can be made non-recurrent as well as recurrent. The Public utility law specifies that unbounded gifts in principle have to be spent by the foundation for its purposes within one year from date of receipt.
Unlike unbounded gifts a bounded gift raises the ad infinitum foundation's capital stock. The foundation's assets are safely and productively invested in order to secure sustained yield, which is watched over by the Managing Committee, the Board of Control as well as by the Tax Inspector's Office. The assets' returns only (e.g. interest) - whereas not the capital stock itself - are used for the foundation's statutory purposes.
Accordingly, if a sponsor endows the ad infinitum foundation with a gift amount of 10,000 Euro, for instance, only the returns of the bounded gift's sum will continually be spent for the foundation's statutory purpose. Supposing returns at the rate of 5% per annum the ad infinitum foundation would be able to spend another 500 Euro yearly for its statutory purposes without touching the "ad infinitum" capital stock.