27 April 2023

TRANSACTION IN OWN SECURITIES

Spirent Communications plc (the "Company") announces today that it has purchased the following number of its ordinary shares, from UBS AG, London Branch (the "Broker").

Ordinary shares

Such purchases form part of the Company's existing share buyback programme and were effected pursuant to the instructions issued to the Broker by the Company on 31 March 2023 as announced on 3 April 2023.

The Company intends to cancel these Shares.

Following the above transactions, the Company will have 605,380,140 Ordinary Shares in issue, which corresponds to the total number of voting rights which may be used by shareholders to determine if 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.  The Company holds no Ordinary Shares in Treasury.

In accordance with Article 5(1)(b) of Regulation (EU) No 596/2014 (the Market Abuse Regulation) (as such legislation forms part of retained EU law as defined in the EU (Withdrawal) Act 2018), a full breakdown of the individual trades made by the Broker on behalf of the Company as part of the buyback programme is set out in the Schedule to this announcement available through the link below:

http://www.rns-pdf.londonstockexchange.com/rns/6093X_1-2023-4-26.pdf

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For further information:

Angus Iveson

Company Secretary

Spirent Communications plc

(+44) 1293 767676