TR-1 Notification of Major Interest in Shares

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

Rosslyn Data Technologies 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): Admission to AIM

x

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

Charles Clark

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

Charles Clark

Guy Clark

Thomas Clark

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

29th April 2014

6. Date on which issuer notified:

16 May 2014

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

12%

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

9,598,848

9,598,848

12.73%

GB00BKX5CP01

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

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

9,598,848

12.73%

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

Proxy Voting:

10. Name of the proxy holder:

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

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

13. Additional information:

Of 9,598,848 Ordinary Shares, 65,432 will be held by Guy Clark, father of Charles Clark, and 52,344 will be held by Thomas Clark, brother of Charles Clark

14. Contact name:

Charles Clark

15. Contact telephone number:

+44 (0) 203 285 8008