Make an Enquiry Here Freephone 0800 092 0800. The Mortgage Shop shared ownership mortgage calculator is for example purposes only and is not a full mortgage illustration to be relied upon. Written mortgage quotes including a calculation of actually available mortgage rates are available on request, simply click on the enquiry link above. Repayment (capital and interest) mortgage calculations can vary between lenders and use of this mortgage calculator should be made to establish a guide and not a definite figure to budget on. Use of this device should not in anyway be taken as an indication of an available mortgage offer from a lender.