You can and in fact should use both. Just be sure to use accrual accounting for management decision-making and if you are allowed cash accounting for tax purposes, according to Doug and Polly White, small business consultants. “In cash accounting, the company recognizes revenue when it receives payment. Expenses are recognized when payments are made”, they write. Not only look at their article, consult with your advisors who had to make this decision. Greater understanding of how the numbers can be analyzed will serve you well through the rest of your career.