Facebook says that the money is transferred immediately but it may take 1-3 business days to make it available to you depending on your bank.
The Issue of Security
Whenever it comes to payments, security is always an issue and on that point, Facebook notes that,
How it Works
The first time you send or receive money in Messenger, you’ll need to add a Visa or MasterCard debit card issued by a US bank to your account. Once you add a debit card, you can create a PIN to provide additional security the next time you send money. On iOS devices you can also enable Touch ID. As always, you can add another layer of authentication to your account at any time. To send money: To receive money:
How will Facebook do it?
Facebook noted that they handle lots of transactions per day as many people pay for their products and services. They want to turn this experience in processing payments into a product where users can send and receive money. However, such services already exist and are probably better than what Facebook is currently offering. Western Union, Moneygram and multiple US banks offer the same. The major question here will be “What’s new that Facebook is adding to the table?” I see Facebook testing the product to make sure it works fine and after it’s done, they will keep adding a few features and benefits to begin competing with existing players. That is why they are starting with sending money for free to get as many people to try out the product. In Uganda and probably Africa, where Mobile money has taken over, this product wouldn’t work. First of all we have a large population that is unbanked (Don’t have a bank account) yet the product depends on you having a bank account. Also the fact that it’s not instant like Mobile money is would also be an issue. But since there is no word of expanding elsewhere currently, we shall not worry about the above.