Final answer:
The financial process of issuing an invoice after services are rendered is known as revenue recognition, which records income when it is earned, not necessarily when payment is received.
Step-by-step explanation:
When a company performs services and issues an invoice, the financial process being described is revenue recognition. Revenue recognition is a cornerstone of accrual accounting that dictates the conditions under which income becomes measurable and reportable. This process ensures that the revenue is recognized when it is earned, regardless of when the payment is actually received.
The other options mentioned are related to different aspects of accounting: Expense allocation deals with spreading out expenditures over different periods, Depreciation is concerned with allocating the cost of tangible assets over their useful lives, and Amortization involves spreading the cost of intangible assets over a specific period.