Pay-to-anyone Coinbase transactions are not supported on Kraken.
When you create a Stacks (STX) deposit address under your Kraken account, a unique ‘Memo’ is also generated. This Memo is an extra piece of information that must be included when sending a STX transaction.
On Kraken, the Memo is used to determine what account a given transaction should be assigned and credited to. This is because all Kraken accounts use a single STX deposit address:
The Memo is numerical and has to be included with all STX deposits to your Kraken account. STX has a nine or ten digit numeric Memo, for example:
123456789 or 1234567890
Always ensure to include the correct Memo before sending your STX deposit. Leaving out this information will lead to significant delays in crediting the transaction to your account, and can be irretrievable in certain cases.
If you forgot to include the memo submit a support request here.