Note: This article is only for historical reference as the fork to which this article refers was completed on August 1, 2017. For more information on Coinbase's plan for Bitcoin Cash please refer to this page: Bitcoin Cash FAQ
August 3, 2017: Update on Bitcoin Cash
July 27, 2017: Update for customers with Bitcoin stored on Coinbase
Do I need to withdraw my BTC from Coinbase?
The UAHF will functionally create two different versions of Bitcoin. In contrast, the UASF will likely not create another version of Bitcoin. However, the UASF may initially cause instability on the Bitcoin network. To ensure the safety of customers’ funds, we will temporarily suspend BTC deposits, withdrawals, and buy/sell starting approximately 4 hours before activation of either fork. If:
(a) you wish to access your coins on the UAHF chain, or
(b) you want to ensure you can access your funds immediately while the UAHF/UASF forks are happening,
you should withdraw your BTC from Coinbase to an external wallet address under your control by July 31.
Is there any risk to simply leaving my BTC in Coinbase during this event?
No, there is no risk to your existing funds. Leaving BTC in your Coinbase wallet will not change anything about your BTC. However, you should move your BTC off Coinbase if you would like access to coins on the new UAHF chain.
If I leave my BTC in Coinbase during the UAHF/UASF, will my BTC turn into the new version, or stay as the old version?
The UAHF is incompatible with the current Bitcoin protocol and will create a separate blockchain. Should the UAHF activate on August 1, Coinbase will not support the new blockchain or its associated coin. Any BTC within customers’ accounts will remain accessible over the main blockchain only, and will not be converted into BTC on the UAHF chain.
The UASF will not alter any customer funds which are stored in Coinbase.
Does this affect funds stored on GDAX as well?
Yes, this affects BTC stored on both Coinbase and GDAX.
What is the UAHF? What is the UASF? What is Segregated Witness?
There are two major upcoming proposals that will affect the Bitcoin protocol and network. These are known as the UAHF and UASF.
The current User Activated Hard Fork (UAHF), including BitcoinABC, is a proposal to alter the Bitcoin protocol by creating a new version of the Bitcoin software, which will operate on its own, separate blockchain.
In contrast, the User Activated Soft Fork (UASF), also known as BIP148, is a proposal to alter the Bitcoin protocol by merging new features into the Bitcoin software, but continue using the same existing blockchain. The proposed features for the upcoming UASF include Segregated Witness, a technology designed to increase the amount of transactions that can be made over the Bitcoin network, and increase the security of the network.
When will the UAHF happen? When will the UASF happen?
The UAHF is scheduled to activate on approximately August 1, 2017. The UASF is scheduled to activate at approximately the same time as the UAHF.
Will Coinbase eventually support withdrawals for the UAHF version of Bitcoin?
We do not plan to offer support for the UAHF chain at this time. You will not be able to withdraw the UAHF version of any Bitcoin from Coinbase. Although we have no plans to support additional blockchains at this time, we will continue to monitor UAHF developments.
Can you recommend which wallet software I should use if I want to withdraw my Bitcoin?
While we cannot recommend any particular third-party wallet, a helpful list of wallet options is available here: https://bitcoin.org/en/choose-your-wallet
Does Coinbase support the UAHF? What about the UASF?
We support the growth and scaling of the Bitcoin network. Although we have no plans to support additional blockchains at this time, we will continue to monitor UAHF/UASF developments.
Will Coinbase keep UAHF coins for itself?
Coinbase does not intend to support or interact with the UAHF chain. If this were to change, Coinbase would make those coins available for customers to withdraw, not keep them.