Do i need to fill out form 3115 from the IRS if I change from cash to accrual?

I heard that it is OK to change the accounting method from cash to accrual. But if I change back to accrual or if I had accrual from the start i would need to fill out that form.

Do i need to fill out form 3115 from the IRS if I change from cash to accrual?
I think you are confusing "automatic consent" with whether or not the form is required. "Automatic consent" means the IRS will accept the form 3115 and approve it without charging you a fee.