In a typical case, a lender will not send a Notice of Default to initiate foreclosure until after the expiration of several months of negotiation with or accomodation to the debtor in search of a solution short of foreclosure. Thus, the lender may be owed several months of mortgage payments (plus interest and penalties) at the time it sends a Notice of Default and it is that cumulative amount which must be tendered to reinstate. The seller will know of the default on the senior, and hence of its option to reinstate, because it will receive a copy of the Notice of Default.