Stichting Kasteel de Haar does not receive any state, provincial or municipal subsidies for its opening as a museum. De Haar relies on its own income from ticket sales, activities and events. For one-off projects such as restorations, redesigns or collection transfer, Kasteel de Haar acquires financial support from various funds and governmental institutions. For long-term regular maintenance of the monuments, De Haar receives state subsidies under the Subsidy Scheme for the Preservation of Monuments.

Since the year 2000, many private and government funds have supported De Haar projects.
Recent projects with support are described below.

Consequences of the Corona pandemic
Castle de Haar made use of the Emergency Measure Overbridge Employment (NOW) of the State, which contributed to keeping employees employed as much as possible while the castle was closed.
Kasteel de Haar also received compensation for the loss of income due to the Corona pandemic from the schemes for private museums of the Ministry of Education, Culture & Science. These schemes were implemented by the Mondriaan Fund.

The necessary adjustments resulting from the Museum Protocol for Responsible Visiting during the pandemic were implemented in 2020 and 2021 with financial support from the Kickstart Culture Fund.
Thanks to the Corona Scheme Employees Collection Policy of the Mondriaan Fund, Kasteel de Haar has been able to appoint a collection officer.

Restoration Carriages.
The restoration of five of De Haar's original thirteen carriages began in 2018 and will be completed in 2022. These restorations are made possible in part by VZW Natuurbehoud Pater David, the Mondriaan Fund, the VSB Fund, the Prince Bernhard Culture Fund and Bonhomme Tielens.

Cross Pond restoration
The restoration of the Cross Pond started in 2019 and will be completed in 2021. This restoration is made possible in part by the Heritage Pearls Fund of the Province of Utrecht.

Hospitable on The Haar
The project Gastvrij op De Haar, in which staff and volunteers are trained in how to receive visitors, is made possible in part by the Mondriaan Fund.

Torendol
The exhibition and tour Torendol was planned for spring 2020 and has been postponed to 2021 due to the closure of the museums due to the pandemic. Torendol includes an art and architecture exhibition throughout the castle, suitable for young and old, along with an active and interactive multimedia family tour (with augmented reality) through the towers, weather corridors and attics of Castle de Haar.
Torendol has been made possible with support from the Elise Mathilde Fonds, the KF Heinfonds, the Prins Bernhard Cultuurfonds and the Fentener van Vlissingen Fonds.

Park access for the disabled
In 2021, the doors to leave the entrance building and enter the park have been modified for the purpose of improving accessibility for the disabled. This has been made possible with subsidy Accessibility from the Municipality of Utrecht.

Paintings Etienne and Hélène
With the proceeds from the Prince Bernhard Culture Fund's mobile collection, the restoration of the portraits of Etienne and Hélène from the permanent display in the Ballroom will begin in 2021.

Funds and governments that have contributed to projects in the past are as follows:
- ANWB Fund
- The BankGiro Lottery (now Friends Lottery)
- Bonhomme Tielens
- Dioraphte
- Elise Mathilde Fund
- Fentener van Vlissingen Fund
- Heritage Pearls Fund via the Province of Utrecht
- Municipality of Utrecht
- KF Hein Fund
- Kickstart Cultural Fund
- MAOC Countess of Bylandt Foundation
- Ministry of Education, Culture & Science
- Mondriaan Fund
- National Art Property Fund
- Prince Bernhard Cultural Fund
- Rabobank Incentive Fund
- SNS Reaal Fund (now Fonds 21)
- TBI Foundation
- Rembrandt Association
- VSB Fund
- Father David Nature Conservation Foundation
- Zabawas