What would increase the coupon rate that is required to enable a bond to be issued at par?

The coupon rate required for a bond to be issued at par increases when market interest rates rise, as investors demand higher returns to compensate for the opportunity cost of investing in bonds over other assets. Additionally, if the bond issuer's credit rating declines or perceived risk increases, investors will require a higher coupon rate to offset the increased risk of default. Lastly, longer maturities typically necessitate higher coupon rates due to greater uncertainty over time.