So the deal is closed. The seller scoops up the checks, the buyer grabs the keys and all is done. Well, sort of.
Sellers often include a provision in the contract rider providing that they are entitled to any tax refunds that the Purchaser receives after the closing which were applicable for the period of time that the Seller owned the unit. For example, suppose a unit closes on June 30, 2011 and it turns out that the unit was entitled to a $1,200 tax refund for the period ending on June 30, 2011. When the tax refund is ultimately received by the Purchaser after the Closing, the Seller would be entitled to that refund AFTER THE CLOSING.
This seems reasonable for condominiums but not necessarily so for co-ops since co-op owners typically do not even benefit from tax refunds as co-op boards usually charge an assessment to each unit owner equal to the amount of a tax refund. If that is the case, then it would be unfair for the Purchaser to have to pay BOTH the co-op and reimburse the Seller for this refund.
A fair solution is to modify the contract rider to provide that the purchaser need not pay the seller any portion of the tax refund received that is ultimately charged back to the purchaser by way of assessment.
The City of New York Department of Finance website has a database which shows the tax refunds per building, but you will need to know the Block and Lot Number of your building to be able to calculate the tax refund for your building.