A memo is a unique 9-digit figure assigned to each Stellar-based cryptocurrency account (e.g. XLM, WLO). It is used to identify the recipient in a transaction. When sending the Stellar-based cryptocurrency, you need to provide the following information:
You must specify your unique memo when transferring Stellar-based cryptocurrencies from an external wallet to Wirex or between Wirex accounts.
When sending Stellar-based cryptocurrencies to external accounts, your recipient may or may not require it.
When you are receiving Stellar-based cryptocurrencies, your sender must also specify their memo, as well as their address.
Learn more about memo