If you are under the qualifying age for state pension credit and claiming for help with your mortgage through a means-tseted benefit it is important to establish whether you qualify under 'new' rules or 'old' rules.

This page provides some guidance but the rules are very complicated and you should seek further advice on how the system applies to you. We recommend that you get further advice by checking with DWP or contacting one of the organisations listed under more advice.

The most difficult problem in working out whether you are treated under 'new' or 'old' rules is that it depends on how much income you have coming in (as well as other factors). If you are making a new claim for benefit after January 2009 you may qualify under 'new' rules, unless your income means your entitlement excluding help with mortgage interest is zero (when you may qualify under 'old' rules). The calculator only provides an estimate of your entitlement, so you can only know which system you are in once you have made a claim.

The differences between how you are treated under 'new' or 'old' rules relate to:

• the limit on the size of mortgage that you can claim for;
• the waiting period before your benefits include an amount for help with mortgage interest;

You should also find out whether you will be subject to a time-limit for receiving help with mortgage interest.

Maximum mortgage under new and old rules

There is a limit on the outstanding mortgage that can be claimed for. This is set at £100,000 under 'old' rules but £200,000 under 'new' rules.

The limit on the outstanding mortgage does not apply if the loan was used to adapt a home or if the house move was necessary:

• to meet the special needs of a disabled person; or
• to provide separate sleeping accommodation for children of different sexes who are aged 10 or over.

The calculator will let you calculate help with your mortgage up to the amount you enter. However, this does not necessarily mean that you will qualify up to this level. Please check that you are entitled to help with the mortgage amount you enter. If you enter a mortgage amount that is above the limit that applies to you then the amount estimated by the calculator will be too high.

Waiting period under new and old rules

Under 'new' rules you qualify for help with mortgage costs after 13 weeks on benefits. Under 'old' rules you qualify for help after 39 weeks. From 1 April 2016 the 13 week limit is being abolished and the 39 week limit will apply to new claims.

The calculator shows your entitlement including any help with mortgage payments you are entitled to. In effect we show the help you qualify for after the waiting period.

Your waiting period may be less than 39 weeks - see exceptions to the 39 week rule.