Holding(s) in Company

For filings with the FCA include the annex

For filings with issuer exclude the annex

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

Tritax Big Box REIT plc

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

√

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

√

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights :

Other (please specify):

CHANGE TO THE TOTAL NUMBER OF VOTING RIGHTS IN ISSUE FOLLOWING THE RECENT PLACING ISSUE

√

3. Full name of person(s) subject to thenotification obligation: iii

Aviva plc & its subsidiaries

4. Full name of shareholder(s) (if different from 3.):iv

Registered Holder:

Available on Request

2,282,744*

Chase (GA Group) Nominees Limited

66,065,219*

Chase Nominees Limited

667,251*

CUIM Nominee Limited

481,863*

HSBC Global Custody Nominee (UK) Limited 15,326,794*

State Street Nominees Limited

6,655,675*

*denotes direct interest

BNP Paribas - London

616,538

Chase Nominees Limited

4,308,962

Vidacos Nominees Limited

4,139,660

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

15 May 2017

6. Date on which issuer notified:

17 May 2017

7. Threshold(s) that is/are crossed orreached: vi, vii

7% to 6% Change at Direct Interest Level (Box 8A & Box 8A+8B)

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

Ordinary SharesGB00BG49KP99

90,076,211*

90,076,211*

100,544,706

91,479,546

9,065,160

6.71%

0.66%

* Includes Right to Recall Loaned Shares (3,698,062)

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

RIGHT TO RECALL LOANED SHARES

N/A

N/A

1,199,300*

* Direct Interest

0.09%

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

101,744,006

7.46%

9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable: xxi

The voting rights are managed and controlled by Aviva Investors Global Services Limited and Friends Provident International Limited, with the following chain of controlled undertakings:-

Aviva Investors Global Services Limited:

· Aviva plc (Parent Company)

· Aviva Group Holdings Limited (wholly owned subsidiary of Aviva plc)

· Aviva Investors Holdings Limited (wholly owned subsidiary of Aviva Group Holdings Limited)

· Aviva Investors Global Services Limited (wholly owned subsidiary of Aviva Investors Holdings Limited)

Friends Provident International Limited:

· Aviva plc (Parent Company)

· Aviva Group Holdings Limited (wholly owned subsidiary of Aviva plc)

· Friends Provident International Limited (wholly owned subsidiary of Aviva Group Holdings Limited)

Proxy Voting:

10. Name of the proxy holder:

See Section 4

11. Number of voting rights proxy holder will ceaseto hold:

12. Date on which proxy holder will cease to holdvoting rights:

13. Additional information:

Figures are based on a total number of voting rights of 1,363,040,998 as per the Company's Result of Placing, Open Offer and Offer for Subscription announcement of 11 May 2017.

14. Contact name:

Neil Whittaker, Aviva plc

15. Contact telephone number:

01603 684420