Depositing Stellar Lumen (XLM) to Bitfinex requires both:
On the deposit page, the deposit address is shown at the top, with the deposit Memo for each of your wallets shown below. To make a deposit to your Exchange wallet, for example, you will need to use the deposit address shown near the top and the deposit Memo next to your Exchange wallet.
Note: Failing to include the Memo as is with no additional or missing symbols/spaces will cause significant delays in crediting the transaction to your account, and can deem the transaction irretrievable.
Stellar (XLM) Account Merge
The Stellar (XLM) “Account Merge” operation transfers the native balance (the amount of XLM an account holds) to another account and removes the source account from the ledger. Account Merge operations are not considered as deposits. Merging Stellar (XLM) accounts to Bitfinex will result in your funds being unrecoverable.
Please contact support if you have any questions or concerns.