## Introduction

When the effective interest rate method is used, the amortization of the bond premium plays a crucial role in accounting for the difference between the bond’s face value and its issue price. This method is commonly used to allocate interest expense and amortize the premium or discount on bonds over their respective terms. In this article, we will explore the concept of bond premium, the effective interest rate method, and how the amortization of the bond premium is calculated.

## Bond Premium and Effective Interest Rate Method

**Bond Premium:** A bond premium occurs when the bond’s issue price is higher than its face value. Investors are willing to pay a premium for bonds when the coupon rate is higher than the prevailing market interest rate. The premium represents the additional interest income that investors expect to earn over the bond’s term.

**Effective Interest Rate Method:** The effective interest rate method is a way to allocate interest expense and amortize the bond premium or discount over the bond’s term. It ensures that the interest expense recognized each period reflects the effective interest rate on the bond.

## Calculating Amortization of Bond Premium

The amortization of bond premium is calculated using the effective interest rate method. Here’s how it is done:

1. Determine the effective interest rate: The effective interest rate is the rate that discounts the bond’s future cash flows to its initial carrying amount. It takes into account the bond’s issue price, face value, coupon rate, and the time to maturity. This rate is usually provided in the bond agreement.

2. Calculate the periodic interest expense: Multiply the carrying amount of the bond at the beginning of each period by the effective interest rate. The carrying amount is the bond’s initial issue price plus or minus any unamortized premium or discount.

3. Calculate the premium amortization: The difference between the periodic interest expense and the bond’s coupon payment represents the premium amortization. If the periodic interest expense is higher than the coupon payment, it means that a portion of the expense is due to the amortization of the premium. Subtract the coupon payment from the periodic interest expense to determine the premium amortization.

4. Adjust the carrying amount: Reduce the carrying amount of the bond by the premium amortization. This adjustment reflects the gradual reduction of the unamortized premium over the bond’s term.

5. Repeat the process: Repeat steps 2-4 for each period until the bond reaches its maturity.

## Example

Let’s consider an example to illustrate the amortization of bond premium:

Suppose a company issues a $1,000 bond with a 5% coupon rate and a maturity period of 5 years. The effective interest rate on the bond is 6%. The bond is issued at a premium of $50.

Using the effective interest rate method, the annual interest expense for the first year would be $60 ($1,000 * 6%). The coupon payment would be $50 ($1,000 * 5%). Therefore, the premium amortization for the first year would be $10 ($60 – $50).

The carrying amount of the bond at the beginning of the second year would be $990 ($1,000 – $10). The interest expense, coupon payment, and premium amortization for the second year would be calculated based on this adjusted carrying amount, and the process continues until the bond matures.

## Conclusion

The effective interest rate method is a useful accounting technique for allocating interest expense and amortizing the bond premium. By using this method, companies can accurately reflect the true cost of borrowing and the gradual reduction of the premium over the bond’s term. Understanding how to calculate the amortization of bond premium is essential for financial reporting and analysis.

## References

– Investopedia: www.investopedia.com

– AccountingTools: www.accountingtools.com

– Corporate Finance Institute: www.corporatefinanceinstitute.com