If I move out of Middlesex County or sell an item of personal property, will my tax bill be prorated? Middlesex County does not prorate personal property.Pay Personal Property Taxes Online enables online payments for personal property tax bills received from Middlesex County. Property Tax Reimbursement Forms (PTR) May Be Filled Out on the Following Days and Times. A single personal property assessment is made for all taxable personal property of the owner located in the city or town. 2. Exemption applications must be filed with your local assessor's office. See our Municipal Profiles for your local assessor's mailing address. Property Tax Forms and Guides. Taxpayers should use these forms and guides to apply for local tax abatements and exemptions and file property returns. With this service, taxpayers can look up and pay bills online for current taxes, delinquent taxes, or sanitation charges.