Bitcoin Unlimited

Bitcoin Unlimited

Investopedia / Laura Porter

What Is Bitcoin Unlimited?

Bitcoin Unlimited was a proposed fork from the Bitcoin blockchain after the community began discussing concerns over slow transaction times and rising fees, and that would allow Bitcoin to process more transactions and reduce fees. It would have accomplished this by allowing for an increase in the block size. The fork was never initiated, but further concern and discussion led to eventual forks.

The Bitcoin Unlimited project joined the Bitcoin Cash (BCH) project and created a client for BCH. Bitcoin Cash changed its name to Bitcoin ABC (Adjustable Block-size Cap) in 2018, then rebranded as eCash (XEC) in May 2021. Thus, in 2022, Bitcoin Unlimited is a client that supports XEC.

Key Takeaways

  • Bitcoin Unlimited was intended to improve transaction speed through scale.
  • It proposed that the size of blocks should be increased and that miners would step up to increase capacity.
  • Bitcoin Unlimited exists as a client for BitcoinABC, which uses the cryptocurrency eCash.

Understanding Bitcoin Unlimited

Bitcoin Unlimited was an attempt to address issues the Bitcoin blockchain issues emerging at the time. The Bitcoin network records transactions on a shared ledger, called a blockchain. Instead of a single database, the ledger is stored on thousands of different computers, where it can be independently verified by any observer.

A program generally referred to as a consensus mechanism verifies transactions, and the people hosting the program and software are called miners. At the time, a new block was created to record the next transaction about every ten minutes on the Bitcoin blockchain.

It still takes the Bitcoin blockchain about ten minutes to open a new block, but applications running on other layers have been designed to speed up the process and reduce transaction fees.

This system is less efficient than legacy systems because it can handle fewer transactions than a centralized database. As Bitcoin payments became more popular, the network began to reach its limits, causing transaction times and fees to increase. Bitcoin Unlimited was one of several proposed software upgrades that would reduce network congestion by increasing Bitcoin's transaction limits.


In 2015, Perter Rizun introduced and began discussing a proposal on Bitcoin Forum to change the block size and create a fork called Bitcoin Unlimited. Encouraged by the discussion and support, Rizun continued working on and promoting Bitcoin Unlimited. Gaining some support from the community, Bitcoin Unlimited was created but ultimately failed to become popular.

However, the block size dispute ultimately caused the Bitcoin network to split in August 2017. Most miners and users remained on the old network, which kept the block size limit at 1 MB. A second cryptocurrency, Bitcoin Cash, was created by those users and miners who changed their software to allow for larger blocks.

For a fork to be successful, it needs to be implemented by the community. In the case of Bitcoin Unlimited, miners did not upload the proposed code to their machines, instead preferring to stay with the original Bitcoin blockchain. This is one of the ways a community guides the development of a blockchain.

Bitcoin Unlimited didn't disappear as many failed forks do. When the BitcoinCash (BCH) fork emerged, the Unlimited team decided to join them but created a client to support the network.

Bitcoin Cash changed its name to Bitcoin Cash ABC in 2018, then rebranded as eCash (XEC) in May 2021, so Bitcoin Unlimited is a client that supports XEC.

How Is Bitcoin Unlimited Different?

Blocks are files where Bitcoin transactions are permanently recorded, like a ledger page or record book. Each time a block is completed, it gives way to the next block in the blockchain. In the Bitcoin network, each block is limited to one megabyte of transaction data every ten minutes.

Bitcoin Unlimited proposed that the size of blocks should be increased and that miners—individuals and companies that provide the computing power to record Bitcoin transactions—would step up to increase capacity.

Bitcoin Unlimited is still under active development, but instead of being a blockchain, cryptocurrency, or payment system, it is an "implementation of the Bitcoin client software" that supports Bitcoin ABC and eCash.

Can Bitcoin Be Unlimited?

By design, there will only ever be 21 million Bitcoin in circulation. The last bitcoin is predicted to be awarded in 2142. The last few rewards will be portions of bitcoin, called satoshis, because the reward halves about every four years. This means that sometime around 2034, the Bitcoin block reward should fall to less than 1 BTC.

How Do I Get Free Bitcoin Rewards?

There isn't a "free" way to receive a bitcoin unless someone gives you one or you win it in a contest. At 2022 prices, it would be an expensive gift. You can mine bitcoin by joining a pool, but you need hardware capable of mining, such as a graphics processing unit or an application-specific integrated circuit miner.

Is Free Bitcoin Real?

Regardless of what you read, there are no free bitcoins unless someone gives one to you. You need compatible hardware and software to mine it, and you need to join a mining pool to have a chance at earning a portion of a block reward. The chances of mining a block and receiving the 6.25 BTC reward by yourself are very minimal.

Article Sources
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  1. Bitcoin Unlimited. "Download."

  2. BitcoinABC. "BCHA Has Been Rebranded To eCash."

  3. Gitlab. "BCH Unlimited Release 1.10.0 With ElectrsCash 3.1."

  4. Bitcoin Forum. "Bitcoin Unlimited: A Peer-to-Peer Electronic Cash System for Planet Earth."

  5. Medium. "Peter R. Rizun."

  6. Bitcoin Unlimited. "About."

  7. Gitlab. "BCHUnlimited."

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