SID stands for Special Improvement District. This fee is assessed by the city to the homeowners. Sellers including home builders are required by law to declare this fee at the initial buyer's due diligence period of an escrow/transaction. Not all properties have an SID fee. Masterplanned communties such as Aliante, Green Valley Ranch and Seven Hills are a few of them that impose this assessments.

As a homeowner you may choose to pay it all or pay as you are billed (quarterly or bi-annually). This will be recorded as a lien on your home and does not cause any problem at sale of your house. This fee simply gets transferred to the new homeowner.