Annual Information Update

National Grid PLC
23 June 2006

23 June 2006

National Grid plc ('National Grid')
And
National Grid Gas plc (NGG)
National Grid Gas Holdings plc (NGGH)
National Grid Electricity Transmission plc (NGET)
NGG Finance plc (NGGF)

-Annual Information Update

This Annual Information Update is issued on the issue of the National Grid
Report and Accounts 2006 and contains information in respect of National Grid
and the listed group entities headlined above as specified in this document.

It is required by and being made pursuant to Article 10 of the Prospectus
Directive as implemented in the United Kingdom and not for any other purpose and
neither the Company, nor any other person, takes responsibility for, or makes
any representation, express or implied, as to the accuracy or completeness of,
the information which it contains. This information is not necessarily up to
date at the date of this annual information update and the issuing Companies do
not undertake any obligation to update any such information in the future.
Furthermore such information may have been prepared in accordance with the laws
or regulations of a particular jurisdiction and may not comply with or meet the
relevant standards of disclosure in any other jurisdiction. This annual
information update does not constitute an offer of any securities addressed to
any person and should not be relied upon by any person.

Section A:

Announcements to the London Stock Exchange by National Grid plc and/or by other
companies headlined, as indicated:

DATE             DETAILS

8.4.05    Notification of Capital Group's interest reduced to 7.98%.

11.4.05   Directors Interests - Share Incentive Plan - monthly update
          - Similar RNS for NGGH

18.4.05   NGG Announcement - Debt Repurchase

19.4.05   Quest Operation

26.4.05   GridAmerica to cease operations

27.4.05   Director appointment  (John Allan)

29.4.05   Notification of Franklin Resources (Templeton) Interest falling below 
          3%.

3.5.05    Quest operation

5.5.05    NGGH Announcement - Debt Repurchase

6.5.05    Notification of Directors' Interests on Appointment (J Allan)

10.5.05   Directors Interests - Share Incentive Plan - monthly update
          -Similar RNS for NGGH

11.5.05   NGG Announcement - Debt Repurchase

17.5.05   Quest Operation

19.5.05   Results for the year ended 31 March 2005
          also released in the names of NGET, NGG, NGGH and NGGF
          -as 'Parent Company Announcement'

23.5.05   Investor Seminar- 20 July 2005.

24.5.05   Executive. Directors' share interests (further operation of the ESOP).
          (One Director, R J Urwin, exercises Sharematch options)

1.6.05    Sales Of Four Gas Distribution Networks Completed

1.6.05    Euro medium Term Note Programme NGG also issues two debt repurchase 
          notifications

2.6.05    NGG Announcement- Debt Repurchase

3.6.05    Exec. Directors' share interests (further operation of the ESOP).

6.6.05    £2 billion return of cash to shareholders

7.6.05    Directors Interests - Share Incentive Plan - monthly update
          (Similar RNS for NGGH )

7.6.05    NGG announcement- Debt Repurchase

8.6.05    ESOT Operation- purchase of more shares

9.6.05    NGG Announcement- Debt Repurchase)

13.6.05   Quest Operation

15.6.05   Annual Report and 2005 AGM and EGM Notices, and return of cash
          Circular, Issued

17.6.05   NGG Announcement- Debt Repurchase

27.6.05   Directors' Share interests- Sharematch Scheme Operation and Partial 
          Lapse of certain Executive Options (similar RNS for NGGH)

28.6.05   NGET Announcement- Debt issue

29.6.05   Deutsche Bank notify a 3.01% interest.

30.6.05   Deutsche Bank interest reduced below 3%.

30.6.05   Directors Interests - Performance Share Plan operation
          (Similar RNS for NGGH)

5.7.05    Quest Operation

6.7.05    ESOT Operation- purchase of more shares
          (Similar RNS for NGGH)

6.7.05    Notification of Capital Group's interest reduced to 6.97%.

11.7.05   Directors Interests - Share Incentive Plan - monthly update
          (Similar RNS for NGGH)

14.7.05   NGG Announcement - Debt Repurchase

18.7.05   Quest Operation

20.7.05   B shares- Commencement of Conditional Dealings

20.7.05   Investor Seminar- UK Gas and Wireless Infrastructure

22.7.05   Deutsche Bank- interest at 3%

26.7.05   Return of cash approval

26.7.05   Change of name approved

26.7.05   AGM and EGM Poll Results

27.7.05   Amended Result of AGM/EGM Poll

27.7.05   Return of Cash- Filing of Prospectus

29.7.05   IFRS Conversion Statement

29.7.05   Quest operation

29.7.05   Barclays interest increased to 4.6%

1.8.05    NGGH  Announcement - commences bond tender offer.

1.8.05    Listing of New Ordinary Shares and B Shares

2.8.05    Goldman Sachs notifies 4.2% interest

4.8.05    Directors interests- John Allan Share purchase

8.8.05    Return of Cash - Results of Elections

9.8.05    Goldman Sachs no longer has notifiable interest

9.8.05    NGGH Announcement - bond tender offer results.

10.8.05   Deutsche Bank notifes 3.54% interest.

11.8.05   Directors Interests - Share Incentive Plan - monthly update
          (Similar RNS for NGGH)

22.8.05   Return of Cash- Repurchase of B Shares.

26.8.05   Publication of Prospectus- Euro Medium Term Note programme.

31.8.05   NGET Announcement - Medium Term Note Programme

1.9.05    Directors' Interests (M Jesanis' 'Thrift Plan' acquires shares).

2.9.05    NGET Announcement- Publication of Prospectus- Euro Medium Term             
          Note programme.

2.9.05    Quest Operation (and E Astle exercises Sharesave options)

2.9.05    Updated Directors interests in shares- following return of cash.

5.9.05    NGET Announcement- - Medium Term Note Programme- issue of debt

5.9.05    Publication of Final Terms- Euro Medium Term Note programme.

6.9.05    Euro Medium Term Note Programme

9.9.05    Directors Interests - Share Incentive Plan - monthly update
          (Similar RNS for NGGH)

9.9.05    Deutsche Bank interest no longer notifiable.

9.9.05    Directors Technical interests- LTIS share purchases.

20.9.05   Quest Operation

23.9.05   Directors Interests- (S. Lucas)- LTIS reinvestment of dividend
          (receipt by Trustee of NG's Aug.05 final dividend) and update to N 
          Winser's B share interest (Similar LTIS only RNS for NGGH)

23.9.05 and 27.9.05 -   NGET Announcements- Prospectus updates- Euro Medium
                        Term Note programme.

27.9.05 and 28.9.05-    NGET Announcement- Euro Medium Tem Note Programme

28.9.05   Publication of Final Terms- National Grid Fixed Rate, due 2010.

29.9.05   Euro Medium Tem Note Programme

30.9.05   National Grid Close period trading update for the six months ended 30 
          September 2005.

4.10.05   Quest operation.

7.10.05   Legal & General notify a 4.02% interest

11.10.05  Quest operation.

11.10.05  Directors Interests - Share Incentive Plan - monthly update
          (Similar-for NGGH)

14.10.05  NGET Prospectus update- Euro Medium Term Note programme.

17.10.05  NGET Euro Medium Tem Note Programme- Issue of Debt

1.11.05   Quest operation

3.11.05   LTIS Operation (transfer of 2001 LTIS award Shares to Director, S 
          Lucas)
          (Similar Notification for NGGH)

8.11.05   Directors Interests - Share Incentive Plan - monthly update
          (Similar-for NGGH)

11.11.05  Morgan Stanley notify a 4.09% interest

15.11.05  Quest operation.

17.11.05  National Grid - Results for the six months ended 30 September 2005
          (also released in the names of NGET, NGG, NGGH and NGGF -as 'National 
          Grid plc- Interims')

18.11.05  NG/NGET Prospectus update- Euro Medium Term Note programme.

23.11.05  NGET Euro Medium Tem Note Programme- Issue of Debt

30.11.05  Deutsche Bank notify a 3.34% interest.

1.12.05   Morgan Stanley Reduce to 3.71% interest.

2.12.05   Quest operation.

5.12.05   CSFB interest falls below 3%

8.12.05   Morgan Stanley interest falls below 3%

8.12.05   Directors Interests - Share Incentive Plan - monthly update
          (Similar-for NGGH)

9.12.05   CSFB interest back above 3%

12.12.05  Deutsche Bank interest falls below 3%

21.12.05  Quest operation.

4.1.06    Investor Calendar for 2006

5.1.06    NGET Accepts Ofgem's price control proposals

9.1.06    Cancellation of NG Deferred Shares

11.1.06   Quest operation.

11.1.06   Directors Interests - Share Incentive Plan - monthly update
          (Similar-for NGGH)

23.1.06   NGGH Debt repurchase

30.1.06   Planned Chief Executive Succession

30.1.06   Directors' Interests (M Jesanis' 'Thrift Plan' acquires shares).

31.01.06  Quest operation.

2.2.06    National Grid Gas plc- Debt Repurchase

7.2.06    Directors Interests - Share Incentive Plan - monthly update
          (Similar-for National Grid Gas Holdings plc)

13.2.06   Quest operation.

13.2.06   Block Listing Six Monthly Return

16.2.06   Agreement to acquire Rhode Island Gas Distribution Business From 
          Southern Union Company.

24.2.06   Discussions with Keyspan Corporation

24.2.06   Director- John Grant- Impending Retirement

24.2.06   Capital Group interest reduced to 5.85%.

24.2.06   Prospectus for the National Grid Gas Holdings plc / National Grid Gas 
          plc Euro 10,000,000,000 Euro Medium Term Note Programme published on
          RNS website.

27.2.06   National Grid announces Acquisition of Keyspan

3.03.06   Quest operation (transfer of all remaining shares in the Quest).

6.3.06    NGGH - disposal of shares by M Cooper

6.3.06    Prospectus for the National Grid Gas Holdings plc / National Grid Gas 
          plc Euro 10,000,000,000 Euro Medium Term Note Programme published on
          RNS website.

          And Prospectus for the National Grid plc/ National Grid Electricity 
          Transmission plc 6,000,000,000 Euro Medium Term Note Programme 
          published on RNS website.

7.3.06    Investor Diary Dates

9.3.06    Directors Interests - Share Incentive Plan - monthly update
          (Similar-for NGGH)

9.3.06    Directors interests- exercise of options/ part disposal- E M Astle

13.3.06   Directors Interests-S Lucas Exercises Sharesave.

14.3.06   Directors Interests-Nick Winser Exercise of options/ part disposal.

20.3.06   National Grid EUR 750m 4.125% Fixed Rate Notes due 2013 - Publication 
          of Final Terms on the RNS website

20.3.06   NGGGH - disposal of shares by M Cooper

21.3.06   Euro Medium Term Note Programme (two releases).

27.3.06   Director's share purchase (Sir John Parker)

30.3.06   Financial Timetable for the year ending 31 March 2007.

30.3.06   National Grid Close period trading update for the year ending 31 March 
          2006.

31.3.06   NGET GBP 200m 1.6449% RPI linked instruments due 2036- Publication of 
          Final Terms on the RNS website.

3.4.06 and    NGET- Medium Tem Note Programme
7.4.06

6.4.06    NGET GBP 50m 1.6747% RPI linked instruments due 2036- Publication of 
          Final Terms on the RNS website AND NGGH GBP 100m 1.6747% RPI linked 
          instruments due 2036- publication of Final Terms on the RNS website.

7.4.06    National Grid Gas plc- Medium Tem Note Programme

10.4.06   Directors Interests - Share Incentive Plan - monthly update
          (Similar-for National Grid Gas Holdings plc)

27.4.06   Directors interests- Lapse of certain Executive Options
          (similar RNS for NGGH -on 28.4.06)

10.5.06   NGET GBP 50m 1.819% RPI-Linked Instruments due 2056 -
          Publication of Final Terms on the RNS website

11.5.06   Directors Interests - Share Incentive Plan - monthly update
          (Similar-for National Grid Gas Holdings plc)

11.5.06   NGET Announcement - Medium Tem Note Programme

12.5.06   NGplc/ NGET Euro 12,000,000,000 Euro Medium Term Note
          Programme to be published on the RNS website.

18.5.06   Results for the year ended 31 March 2006 also released in the names of 
          NGET, NGGplc, NGGHplc and NGGFplc -as 'National Grid plc- annual 
          results')

19.5.06   NGplc/ NGET Euro 12,000,000,000 Euro Medium Term Note Prospectus                              
          published on the RNS website.

23.5.06   NGGH /NGGplc 10,000,000,000 Euro Medium Term Note Programme
          published on the RNS website.

23.5.06   Director's share purchase (Sir John Parker)

25.5.06   NGET GBP 150m 1.823% RPI-Linked Instruments due 2056 - Publication 
          of Final Terms on the RNS website

26.5.06   NGET- Issue of Debt

30.5.06   Directors interests- (Steve Lucas share disposal)
          (similar RNS for NGGH)

1.6.06    NGplc/ NGET Euro 250,000,000 5.25 per cent instruments due 2011. 
          Final Terms published on the RNS website.

2.6.06    National Grid Euro Medium Term note Programme- Issue Of Debt

6.6.06    ESOT Operation- purchase of more shares

6.6.06    Barclays interest reduced to 3.86%.

9.6.06    Directors Interests - Share Incentive Plan - monthly update
          (Similar-for National Grid Gas Holdings plc-
          and lapse of Executive. Options /Director's disposal)

9.6.06    Morgan Stanley notify a 3.01% interest.

13.6.06   Morgan Stanley interest falls below 3%

16.6.06   Deferred Share Plan Awards- and ESOT

20.6.06   Publication of Annual Report and Accounts



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Section B:



Filings at UK Companies House by National Grid plc- the listed group holding
entity:



During the period, National Grid plc made the following filings:



Forms 88(2) in respect of various allotments of shares under the National Grid
Share Schemes.



5.4.05 and 5.4.06- Annual Returns.

11.5.05   Director Appointed (J Allan)

26.7.05   Company name changed (from National Grid Transco plc)

30.7.05.  Annual Report and Accounts (2004/05).

8.8.05    Form 122 (Subdivision and consolidation of share capital)

August 05 Adoption of New Articles and Form 123 (increase in share capital
          and creation of 'B' shares). And filing of other resolutions passed at 
          the 2005 AGM.

14.9.05   Form 169 - repurchase of 'B' shares

8.2.06    Form 122 - cancellation of 'deferred shares'

16.6.06   Change of Directors particulars

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 Section C:



Filings with the US Securities and Exchange Commission (the 'SEC')



National Grid plc Form 20-F for the fiscal year ended March 31, 2005

National Grid plc Form 6-K dated April 5, 2005

National Grid plc Form 6-K dated May 3, 2005

National Grid plc Form 6-K dated May 19, 2005

National Grid plc Form 6-K dated June 1, 2005

National Grid plc Form 6-K dated June 6, 2005

National Grid plc Form 6-K dated June 15, 2005

National Grid plc Form 6-K dated June 15, 2005

National Grid plc Form 6-K dated July 6, 2005

National Grid plc Form 6-K dated July 26, 2005

National Grid plc Form 6-K dated August 1, 2005

National Grid plc Form 6-K dated September 15, 2005

National Grid plc Form 6-K dated September 30, 2005

National Grid plc Form 6-K dated November 1, 2005

National Grid plc Form 6-K dated November 17, 2005

National Grid plc Form 6-K dated December 5, 2005

National Grid plc Form 6-K dated January 5, 2006

National Grid plc Form 6-K dated January 30, 2006

National Grid plc Form 6-K dated February 6, 2006

National Grid plc Form 6-K dated February 17, 2006

National Grid plc Form 6-K dated February 24, 2006

National Grid plc Form 6-K dated February 27, 2006

National Grid plc Form 6-K dated March 30, 2006

National Grid plc Form 6-K dated May 2, 2006

National Grid plc Form 6-K dated May 18, 2006

National Grid plc Form 6-K dated June 5, 2006

National Grid plc Form 6-K dated June 20, 2006

National Grid plc Form 6-K dated June 20, 2006

National Grid plc Form 20-F for fiscal year ended March 31, 2006

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Contact for further information: D C Forward, Assistant Secretary 0207 004 3226



Note: Alternatively, detailed information may also be obtained from the London
Stock Exchange (Section A information) or UK Companies House (Section B
information) or the US Securities and Exchange Commission (Section C
information) as appropriate.




                      This information is provided by RNS
            The company news service from the London Stock Exchange