Following the announcement of the Bureau of the Royal Household on the passing of Her Royal Highness Princess Bajrakitiyabha Narendiradebyavati Kromluangrajasarinisiribajra Mahavajrarajadhita, the Office of the Permanent Secretary, Prime Minister’s Office, on 12 June 2026 outlined mourning guidelines, as follows:

- All government offices, state enterprises, and educational institutions will lower the national flag to half-mast for 15 days, starting from 12 June 2026 onward.

- Government officials, state enterprise employees, and state personnel will observe a 15-day mourning period from 12 June 2026 onward by wearing proper mourning attire (black and/or white).

- The display of the royal portrait of Her Royal Highness should be considered as appropriate, and the portrait can be downloaded from the Government Public Relations Department’s website, www.prd.go.th .

- In organizing activities in accordance with traditional practices or on important occasions, organizers are encouraged to exercise discretion, and formats of activities might be adjusted appropriately to reflect the national atmosphere of mourning.

- As for the private sector and the general public, they are requested to fly the national flag at half-mast for 15 days, starting from 12 June 2026 onward, and to use their own discretion regarding mourning dress and duration.