An invoicee is a person, organization, or agency that will receive an invoice.
An invoice is an amount that will be billed to the invoicee.
For example Surfing on the internet Cafe, the surfer/user is the invoicee to the Cafe owner, the Cafe owner will bill the amount as per usage charge(s) in the form of 'invoice' which is then payable by the 'invoicee' (surfer/user).
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abhirajcb