How much is expensed on a 18600 prepaid two year insurance?

Thanks

More details please.

When was this policy purchased, when did it go into effect and what is the current date that you are looking at?

When you have paid such an amount you would have passed the entry as:

Prepaid insurance a/c... dr 18600
To cash / bank a/c 18600

Now , when your 1st closing accounting date you will treat such amount as an expense so,

Insurance a/c... dr 9300
To prepaid ins. 9300

This is debited with the first year insurance amount

Similarly for the next year you do the same.

My eyes must be failing me quite bad because when I read this question, I don't remember seeing the words, “two year”

Since this is a 2 years policy, the answer that sajalarora has provides is correct.

Time of Purchase:
Dr. Prepaid Insurance 18,600
Cr. Cash 18,600

Year End Adjustment:
Dr. Insurance Expense 9,300 (18,600 x .5)
Cr. Prepaid Insurance 9,300