Mutual fund units can be held in your demat account, in both forms in demat account or in physical (statement of account) form. The holding is in digital mode and no paper / physical certificate is issued as such. The biggest advantage of a demat account is you get to hold most of your financial investments such as shares, sovereign gold bonds, and corporate bonds in a single account. It makes tracking simple and with NSDL CAS you can track all your investments on monthly basis.
Units held in SOA form can be converted to demat form later.
Please note that NRIs can also opt to hold/convert units in a demat account, provided they have a demat account. If the demat units need to be converted to a physical / SOA form, a dematerialisation reconversion request form must be submitted to the DP. NSDL has further digitalised conversion and reconversion requests by providing API-based integration with DP front-end applications, further enabling investors to submit DRF / RRF online.