When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept. When buying and selling a house, these six types of invoices must be kept.