First-time buyers qualify for Stamp Duty relief if they buy a property for less than £500,000. However, if you were to get a joint mortgage with a parent or a family member that owns or has owned a home, you wouldn’t qualify for this exemption. Worse still, if they do own a home, you and the other party would need to pay 3% Stamp Duty on top of the standard rate as your property would count as a second home. This isn’t the case with a JBSP mortgage. If you opt for this type of mortgage, you will be exempt from paying Stamp Duty as the supporting parties wouldn’t be named on the property deeds.