Dematerialization is the process of converting physical share certificates into electronic form. The process involves opening a Demat account with a Depository Participant (DP), submitting the share certificates for dematerialization, and receiving an equivalent number of shares in electronic form in the Demat account.

However, not all share certificates can be dematerialized. Only shares of companies that have entered into an agreement with a Depository, such as NSDL (National Securities Depository Limited) or CDSL (Central Depository Services Limited), can be dematerialized. Therefore, if a company has not entered into an agreement with a Depository, its shares cannot be held in electronic form.

Moreover, some companies may issue shares that are not eligible for dematerialization. These shares are typically in physical form only and cannot be held in electronic form. In such cases, the only way to transfer ownership of these shares is by executing a physical transfer deed.

It is also important to note that the decision to dematerialize share certificates is at the discretion of the shareholder. While some companies may encourage shareholders to hold shares in electronic form, it is not mandatory. Shareholders have the option to hold their shares in physical form or in electronic form.

Furthermore, in some cases, share certificates may not be immediately eligible for dematerialization. For example, if the share certificates are under pledge, lien, or any other encumbrance, they cannot be dematerialized until the pledge, lien, or encumbrance is removed. Similarly, if the share certificates are the subject of any legal proceedings or court orders, they cannot be dematerialized until the proceedings or orders are resolved.

In conclusion, not all share certificates can be dematerialized. Only shares of companies that have entered into an agreement with a Depository can be held in electronic form. Shareholders also have the option to hold their shares in physical form. Additionally, if the share certificates are under pledge, lien, or any other encumbrance, or if they are the subject of any legal proceedings or court orders, they cannot be dematerialized until the issues are resolved.