Delete your account from Settings → Privacy → Delete Account. You then get about 48 hours to change your mind. After that it's permanent.
Steps
Open Settings → Privacy.
Select Delete Account.
Confirm when prompted.
Your account keeps working normally through those 48 hours, and you can cancel the deletion at any point inside them.
What gets deleted
Once the window closes, your account goes, and so do your wishlists, wishes, reservations, and saved searches. None of it can be brought back, there's no backup to restore from, and Wishpicks stops emailing you.
Anyone you shared a list with loses their access at the same moment, and reservations sitting on those lists go too.
Good to know
Wishpicks Plus is billed separately. Check your subscription before you delete, or you can end up paying for a plan you no longer have a way to reach.
You don't have to delete anything just to change your details. And if you're unsure, contact support while the window is still open. We answer on business days, so weekend and holiday messages get picked up the next working day.
Related
"What happens when I delete my account — can I get it back?"
"How do I change my email or profile name?"
"How do I cancel, pause, or change my Wishpicks Plus subscription?"