on receipt of

It means "upon receiving".
For example if you e-mail a company to ask if they've got something in stock that you want, they can reply in two ways.
Firstly they could say- "Yes we have it in stock for 20 dollars including shipping costs and will despatch it to you when you send us 20 dollars"

Or secondly they could say- "Yes we have it in stock for 20 dollars including shipping costs and will despatch it to you upon receipt of of 20 dollars"

See, "upon receipt of", or "upon receiving" simply means "when you send us"..

"On receipt of" means upon receiving dear. For example,You will always be emailed to confirm receipt of your order once it has been received.

Why do you keep writing "dear" in your posts?

on receipt of = upon receipt of = when I get

Why do you keep writing posts, Contrex? I guess you think people like to put their trust in a thief, a plagiarizer, a language teacher who knows squat about his subject.