It depends on what you mean here. We can allocate data to your MTN contract SIM if you sign up for APN Mobile Data, and change your device data APN to 'afrihost'.
Otherwise you must order a SIM from us, which has been setup for the Afrihost APN on the MTN network.
Maybe you can clarify what you mean here so I can give you more specific advice.
UPDATE: We now offer our APN on MTN PrePaid SIM cards. You can now sign up using your existing SIM even if it is not a MTN contract.