The 70% royalty option is not automatic and not always the better deal. Here is exactly how KDP's 35% and 70% ebook tiers work, what the delivery fee really costs, how paperback and hardcover royalties are computed, and the pricing traps that quietly cut your royalty in half.
By default, Amazon withholds 30% of your US royalties if you are not a US person — and a five-minute tax interview with the right treaty claim can cut that to 0% for many countries. Here is how KDP withholding actually works, what the W-8BEN does, and the mistakes that quietly cost authors thousands.
Kindle Unlimited doesn't pay per borrow — it pays per normalized page read, at a rate Amazon derives each month from a global fund and only announces mid-following-month. Here is how KENPC works, what a page read is actually worth per marketplace, and how to compute what your reads really earn.
KDP pays royalties roughly 60 days after the end of the month they were earned — per marketplace, per currency, and only above certain thresholds for some payment methods. Here is the full payment timeline, what actually delays a payment, and a checklist for the classic 'why hasn't KDP paid me' panic.