Total Voting Rights Update

NIOX Group plc

(the "Company")

Total Voting Rights Update

1 May 2025

NIOX Group plc (AIM: NIOX) confirms that, following the exercise of options over a total of 1,012,391 Ordinary Shares of 0.08p ("Ordinary Shares") by certain employees under the Company's share option schemes, the Company's issued share capital consists of 409,355,947 Ordinary Shares in issue, with 10,000,000 Ordinary Shares held in treasury. Consequently, the total voting rights of the Company are 399,355,947.

Admission of the new Ordinary Shares issued during the month has been satisfied in each case via the block listing for the relevant option scheme.

The above figure of 399,355,947 may be used by shareholders as the denominator for the calculations by which they will determine whether they are required to notify their interest in or a change to their interest in the Company under the FCA's Disclosure Guidance and Transparency Rules.

-Ends-