when to claim rental deposit income

[Stephen Race]

Hi, I have short term rental properties renting by the week. I take a 50% refundable deposit at reservation time, then the balance 30 days before arrival. I take deposits up to a year before arrival. For tax purposes, I am using cash method, so I should claim the income when it is received. I had a CPA tell me that since it is refundable, that I don't have to claim it until it becomes nonrefundable (30 days before). This would significantly reduce my tax burden this year, but I want a second opinion on the legitimacy of this approach.

Thanks.