Any person who has ever attempted to buy or exchange cryptocurrency has encountered the term “transaction ID”. So what exactly does it mean?
What Is A Transaction ID?
A transaction ID, also known as TXID or transaction hash, is a unique set of characters assigned to every crypto operation. It serves as proof that a transaction was validated and added to the blockchain.
What You Need To Know About Transaction IDs
One of the most famous TXID examples in the history of crypto is the first-ever Bitcoin transaction sent by Satoshi Nakamoto to Hal Finney in 2010:
f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16
Once a transaction ID similar to this is created, users can find it via a block explorer. There are two main purposes for doing it:
- To receive a confirmation that the transaction was complete, similar to getting a receipt at a store.
- To look up transaction details, including the sending and receiving addresses, date and time, transfer amount, network fees, etc.
Note that when looking up a TXID, you must use the block explorer that is designed for a specific blockchain. For instance, to find an ETH transaction, you need to use an Ethereum block explorer. This means that if you try to search for a transaction ID through the wrong tool, you either won’t see anything or will come across incorrect information.
The transaction ID definition would not be complete without mentioning the case where two separate Coinbase transfers happened to have the same TXID. This issue occurred because both transactions used the same address when withdrawing the block reward from two different blocks.
Henceforth, such errors were avoided with the help of BIP 30, which introduced a rule that prevented blocks from containing an existing transaction ID. Later on, BIP 34 solidified this solution by making it mandatory for Coinbase to include the height of the mined block to the transaction’s scriptSig.
