Blockchain based decentralized currencies are getting much attention these days and being used widely and deployed commercially, many popular platforms are accepting them as a mode of payment. The most popular among all is Bitcoin (BTC) has achieved great success, but these increased transaction volumes introduced problems like low throughput and high transaction processing time. It's not just with the Bitcoin but also other currencies based on Bitcoin which basically use proof of work principle to register a transaction on distributed ledger also facing similar issues leading to question of scalability of blockchain. This paper focuses on the solutions which can be implemented to make the blockchain scalable.