UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March, 2006 SPIRENT plc _____________________________________________________________________ (Translation of registrant's name into English) Spirent House, Crawley Business Quarter, Fleming Way, Crawley, West Sussex RH10 9QL, UK. _____________________________________________________________________ (Address of principal executive offices) Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F. Form 20-F X Form 40-F..... Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934. Yes ..... No X If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82- ________ Spirent plc (the "Company") Annual Information Update 27 March 2006 In accordance with Section 5.2 of the Prospectus Rules, the Company submits its Annual Information Update which refers to information that has been published or made available to the public in the 12 months up to and including 24 March 2006. In accordance with the provisions of Article 27(3) of the Prospectus Directive Regulation, it is acknowledged that some of the information referred to in this update was up to date at the time the information was published but may now be out of date. Information is referred to in this update rather than included in full. 1.Announcements listed below were published via a Regulatory Information Service Date Headline 24-Mar-06 Annual Report and Accounts 21-Mar-06 Holding(s) in Company 17-Mar-06 Holding(s) in Company 15-Mar-06 Director/PDMR Shareholding (Sharesave Trust) 14-Mar-06 Holding(s) in Company 09-Mar-06 Additional Listing 08-Mar-06 Director/PDMR Shareholding (Sharesave Trust) 01-Mar-06 Director/PDMR Shareholding (Sharesave Trust) 28-Feb-06 Holding(s) in Company 28-Feb-06 Holding(s) in Company 23-Feb-06 Final Results 20-Feb-06 Holding(s) in Company 20-Feb-06 Holding(s) in Company 15-Feb-06 Completion of Disposal of Network Products Division 14-Feb-06 Director/PDMR Shareholding (Sharesave Trust) 13-Feb-06 Acquisition of QuadTex Systems, Inc 09-Feb-06 Holding(s) in Company 01-Feb-06 Director/PDMR Shareholding (Sharesave Trust) 26-Jan-06 Notice of Results 24-Jan-06 Result of EGM 23-Jan-06 Acquisition of SwissQual Holding AG 20-Jan-06 Holding(s) in Company 17-Jan-06 Director/PDMR Shareholding (Sharesave Trust) 06-Jan-06 Blocklisting Interim Review 29-Dec-05 Director/PDMR Shareholding (Sharesave Trust) 20-Dec-05 Director/PDMR Shareholding (Sharesave Trust) 19-Dec-05 Holding(s) in Company 19-Dec-05 Holding(s) in Company 16-Dec-05 Doc re. (Proposed Disposal) 15-Dec-05 Proposed Disposal of Network Products Division 12-Dec-05 Holding(s) in Company 06-Dec-05 Director/PDMR Shareholding (Sharesave Trust) 01-Dec-05 Director/PDMR Shareholding (Sharesave Trust) 14-Nov-05 Holding(s) in Company 02-Nov-05 Holding(s) in Company 01-Nov-05 Holding(s) in Company 29-Sep-05 Holding(s) in Company 28-Sep-05 Holding(s) in Company 27-Sep-05 Holding(s) in Company 19-Sep-05 Re: Network Products Division 12-Sep-05 Holding(s) in Company 26-Aug-05 Director/PDMR Shareholding (Eric Hutchinson) 26-Aug-05 Director/PDMR Shareholding (Anders Gustafsson) 26-Aug-05 Doc re. Interim Report 2005 11-Aug-05 Interim Results 02-Aug-05 Holding(s) in Company 15-Jul-05 Doc re. Transition to IFRS 13-Jul-05 Notice of Results 08-Jul-05 Blocklisting Interim Review 29-Jun-05 Restructuring of Division 28-Jun-05 Holding(s) in Company 27-Jun-05 Holding(s) in Company 22-Jun-05 Holding(s) in Company 20-Jun-05 Holding(s) in Company 20-Jun-05 Holding(s) in Company 15-Jun-05 Additional Listing 01-Jun-05 Holding(s) in Company 11-May-05 Director Shareholding (Eric Hutchinson) 06-May-05 Holding(s) in Company 05-May-05 Holding(s) in Company 04-May-05 Result of AGM & EGM 03-May-05 Holding(s) in Company 27-Apr-05 Director Shareholding (Eric Hutchinson) 26-Apr-05 Holding(s) in Company 26-Apr-05 Holding(s) in Company 22-Apr-05 Holding(s) in Company 22-Apr-05 Holding(s) in Company 21-Apr-05 Trading Statement 15-Apr-05 Notice of EGM 11-Apr-05 Holding(s) in Company 04-Apr-05 Annual Report and Accounts 04-Apr-05 Holding(s) in Company 31-Mar-05 Holding(s) in Company 04-Mar-05 Holding(s) in Company 28-Feb-05 Holding(s) in Company 25-Feb-05 Director Shareholding (John Weston) 25-Feb-05 Director Shareholding (Anders Gustafsson) 24-Feb-05 Final Results Copies of the above announcements can be obtained from the London Stock Exchange website at www.londonstockexchange.com 2. Documents filed at Companies House The Company has also made the following filings with the Registrar of Companies for England and Wales. Date Type Description 24/03/2006 88(2)R Allotment of Shares 23/03/2006 88(2)R Allotment of Shares 20/03/2006 88(2)R Allotment of Shares 16/03/2006 88(2)R Allotment of Shares 16/03/2006 88(2)R Allotment of Shares 16/03/2006 88(2)R Allotment of Shares 16/03/2006 88(2)R Allotment of Shares 10/03/2006 88(2)R Allotment of Shares 10/03/2006 88(2)R Allotment of Shares 08/03/2006 88(2)R Allotment of Shares 08/03/2006 88(2)R Allotment of Shares 08/03/2006 88(2)R Allotment of Shares 03/03/2006 88(2)R Allotment of Shares 01/03/2006 88(2)R Allotment of Shares 20/02/2006 88(2)R Allotment of Shares 14/02/2006 88(2)R Allotment of Shares 08/02/2006 88(2)R Allotment of Shares 08/02/2006 88(2)R Allotment of Shares 24/01/2006 88(2)R Allotment of Shares 19/01/2006 88(2)R Allotment of Shares 17/01/2006 88(2)R Allotment of Shares 10/01/2006 88(2)R Allotment of Shares 09/01/2006 88(2)R Allotment of Shares 03/01/2006 88(2)R Allotment of Shares 28/12/2005 88(2)R Allotment of Shares 14/12/2005 88(2)R Allotment of Shares 12/12/2005 88(2)R Allotment of Shares 05/12/2005 88(2)R Allotment of Shares 05/12/2005 88(2)R Allotment of Shares 02/12/2005 88(2)R Allotment of Shares 11/11/2005 88(2)R Allotment of Shares 08/11/2005 88(2)R Allotment of Shares 02/11/2005 88(2)R Allotment of Shares 02/11/2005 88(2)R Allotment of Shares 01/11/2005 88(2)R Allotment of Shares 24/10/2005 88(2)R Allotment of Shares 24/10/2005 88(2)R Allotment of Shares 24/10/2005 88(2)R Allotment of Shares 14/10/2005 88(2)R Allotment of Shares 13/10/2005 88(2)R Allotment of Shares 13/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 11/10/2005 88(2)R Allotment of Shares 19/09/2005 88(2)R Allotment of Shares 08/09/2005 88(2)R Allotment of Shares 08/09/2005 88(2)R Allotment of Shares 05/09/2005 88(2)R Allotment of Shares 02/09/2005 88(2)R Allotment of Shares 02/09/2005 88(2)R Allotment of Shares 31/08/2005 88(2)R Allotment of Shares 31/08/2005 88(2)R Allotment of Shares 31/08/2005 88(2)R Allotment of Shares 31/08/2005 88(2)R Allotment of Shares 31/08/2005 88(2)R Allotment of Shares 31/08/2005 88(2)R Allotment of Shares 12/08/2005 88(2)R Allotment of Shares 12/08/2005 88(2)R Allotment of Shares 28/07/2005 88(2)R Allotment of Shares 28/07/2005 88(2)R Allotment of Shares 28/07/2005 88(2)R Allotment of Shares 15/07/2005 88(2)R Allotment of Shares 12/07/2005 88(2)R Allotment of Shares 12/07/2005 88(2)R Allotment of Shares 09/07/2005 88(2)R Allotment of Shares 09/07/2005 88(2)R Allotment of Shares 06/07/2005 88(2)R Allotment of Shares 04/07/2005 363a Annual Return 28/06/2005 88(2)R Allotment of Shares 23/06/2005 88(2)R Allotment of Shares 18/06/2005 88(2)R Allotment of Shares 16/06/2005 88(2)R Allotment of Shares 16/06/2005 88(2)R Allotment of Shares 03/06/2005 88(2)R Allotment of Shares 24/05/2005 88(2)R Allotment of Shares 20/05/2005 288b Resignation of Director 17/05/2005 88(2)R Allotment of Shares 17/05/2005 AA Group Company Accounts 16/05/2005 Resolution Disapplication of pre-emption rights; Authority to allot securities; Permission to purchase own shares; Adoption of new Articles of Association 10/05/2005 88(2)R Allotment of Shares 29/04/2005 88(2)R Allotment of Shares 27/04/2005 88(2)R Allotment of Shares 20/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 14/04/2005 88(2)R Allotment of Shares 06/04/2005 88(2)R Allotment of Shares 05/04/2005 88(2)R Allotment of Shares 05/04/2005 88(2)R Allotment of Shares 22/03/2005 88(2)R Allotment of Shares 22/03/2005 88(2)R Allotment of Shares 18/03/2005 88(2)R Allotment of Shares 15/03/2005 88(2)R Allotment of Shares 15/03/2005 88(2)R Allotment of Shares 14/03/2005 88(2)R Allotment of Shares 11/03/2005 88(2)R Allotment of Shares 11/03/2005 88(2)R Allotment of Shares 11/03/2005 88(2)R Allotment of Shares 11/03/2005 88(2)R Allotment of Shares 08/03/2005 88(2)R Allotment of Shares 28/02/2005 88(2)R Allotment of Shares 28/02/2005 88(2)R Allotment of Shares 24/02/2005 88(2)R Allotment of Shares 22/02/2005 88(2)R Allotment of Shares 21/02/2005 88(2)R Allotment of Shares 11/02/2005 88(2)R Allotment of Shares 09/02/2005 88(2)R Allotment of Shares 02/02/2005 88(2)R Allotment of Shares Copies of these documents can be obtained from: Companies House Crown Way Maindy Cardiff CF14 3UZ United Kingdom Tel: +44 (0) 870 333 3636 Email: enquiries@companies-house.gov.uk If you are a registered user, you can access these filings through Companies House Direct at www.direct.companieshouse.gov.uk 3. Documents despatched to members The following documents have been despatched by the Company to holders of its securities during the period: Notice of AGM 2005 dated 16 March 2005 Annual Report 2004 Notice of EGM dated 11 April 2005 Interim Report 2005 Circular relating to proposed disposal of HellermannTyton Division dated 15 December 2005 Notice of AGM 2006 dated 15 March 2006 Annual Report 2005 All the above documents can be found on the Company's website at www.spirent.com Alternatively, copies of information released can be obtained through the Company Secretary at the Company's registered office: Spirent House Crawley Business Quarter Fleming Way Crawley West Sussex RH10 9QL United Kingdom Tel: +44 (0) 1293 767676 Michael Anscombe Deputy Company Secretary Spirent plc Signatures Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. ______LUKE THOMAS______ (Registrant) Date 27 March, 2006 By ____/s/ Luke Thomas____ (Signature)*