The conversion request can be presented at any time, except after the Board of Directors of the company has made a decision to convene the General Meeting. If a conversion request is made before the next General Meeting, it is considered to be received and will be decided after the conclusion of the meeting.
It is important to note that your may not issue preference shares or convert any issued shares into preference shares unless the relevant rights pertaining to those preference shares have been set out in your company’s memorandum or articles of association. These include voting rights, whether the dividends associated are cumulative or non-cumulative, and whether there is a right to participate in the company’s surplus assets and profits.
Here is some information to help you with the process of Conversion of Shares.