The phrase "depend upon" is commonly used to indicate reliance on something or someone. However, there are several synonyms that can be used to express this same idea. "Rely on" is a popular alternative that implies a sense of trust and dependence. "Count on" is another synonym that is often used when indicating a predictable outcome or certain result. "Lean on" is a more figurative option that evokes imagery of support and stability. And finally, "bank on" suggests a confident expectation or reliance on something to come through. These synonyms for "depend upon" can help to add variety and depth to your writing and communication.