Most affiliate systems rely on cookies or referral tokens, so if a user clicks a partner link, a cookie may store the referral for a set window like 7–30 days. If the person signs up later, attribution often still works, but switching devices complicates it because cookies don't always transfer across phones and computers. Some platforms use email-based or server-side tracking to reconnect users, but many don't. So the safe answer is: it's not guaranteed unless BMF.io explicitly supports cross-device attribution or logged-in tracking across sessions. Checking their affiliate policy is the only way to know for sure.