You should always ask for 100% up-front payment and offer 100% money-back guarantee for your work.
This is especially important for project-based services. It avoids scope creep, tightens the schedule, and you will have peace of mind if the client goes dark. But there is more to it.
When a client refuses to pay up-front, it’s either a trust issue or the client doesn’t have the budget.
Both are huge red flags.
If the budget isn’t there… that’s a no-brainer, right? If, on the other hand, your clientele doesn’t perceive you as trustworthy, it’s a branding/positioning issue on your side.
Work that out until your clients would be happy to pay for a spot on your calendar.