Used to mean as soon as something, such as a letter, payment, or document, is received.
“Upon receipt of your payment, we will process your order within 48 hours.”
“Please sign and return the form upon receipt of this letter.”
In Reading Part 1, formal letters use 'upon receipt' to describe what should happen immediately after something arrives, such as a payment or application. This phrase is a common paraphrase target, so look for simpler wording like 'as soon as you get' in answer choices.
Synonyms: as soon as received, immediately after receiving