The 6 or 12 year rule is a grey area. Most people think that when you have a shortfall, it becomes a 'simple' debt and therefore is statute barred after 6 years. However, some say that the shortfall is subject to the same rules as the original mortgage and therefore expires after 12 years.(posted 7427 days ago)But when does the 6 or 12 years start? I suggest that you read through this site for further information on this subject rather than my repeating it here and there are several views on this.