Payment of third-quarter tax bills are due Feb. 1. Both the third- and fourth-quarter tax bills were mailed out Dec. 31. Property owners should keep the bill stub for the fourth quarter in a safe place because there will not be a separate mailing for that tax bill, which is due May 1. The two bills are considered actual bills and reflect this fiscal year’s tax rate and valuation of property. Those who wish to contest their valuation must file an abatement request with the town assessor’s office by Feb. 1. Questions about tax payments should be directed to the tax collector’s office at 978-692-5506. Questions regarding valuation or mailing address changes should be directed to the assessor’s office at 978-692-5504. To view or pay a tax bill online, visit westfordma.gov/collector.