Do I need a bank account with Achiievers to subscribe for an IPO?

No. The broker doesn't offer banking services. You can apply for an IPO at Achiievers with any bank account. The amount for IPO subscription stays in your bank account until the allotment is done. If you get the allotment of the shares, the money is debited from that account. It reduces the risk and waiting period to get the money back in the account.