Hi Samuel,
Milestones are escrowed funds done by the client for a Fixed Price contract. Fixed-price contracts do not bill to your client automatically, but are covered by Upwork Fixed-Price Protection. The client makes a deposit into escrow and sets up a milestone. When you submit the milestone deliverable, the client releases the funds.
When your client releases a milestone or final payment on a fixed-price job, it immediately shows as pending on your financial account. They become available after the standard five-day security period.
