Depends on the state where the property is located. Generally, the roll back taxes are paid prior to a plat being legally filed with the recording agency (county or parish records dept) and/or a subdivision being approved and signed by the various entitlement agencies (city, county, drainage/irrigation districts, municipal utility districts etc). A tax certificate needs to be attached in some form to the plat or subdivision.
As to who pays them, its a negotiating issue. Either party can pay them and depending on the overall price its whoever has a greater interest to complete the transaction.
In some states, roll back taxes can be significant, so they should be considered when purchasing a property for an alternative use. 4 or 5 years times the annual rate on the value differential plus interest is not uncommon. hope that helps.
Dec 2, 2015