Accrual/Deferral Posting

Dear all,

In SAP, Accrual/Deferral is used to spread an expense or revenue to each month after/before receiving an invoice. My scenario is: For each year, I must pay an invoice for insurance premium from the beginning of year. But I want to spread this expense to 12 months and post it at the beginning of each month. How should I use accrual/deferral in this case ? Why each accrual/deferral document must be reversed ?

Thank you very much for your help.

Sylvecat.