Los Alamos County reminds property owners second-half taxes due May 11

A second-half property tax bill left unpaid after 5 p.m. Monday, May 11, can trigger delinquent charges in Los Alamos County, and the county is reminding property owners that the responsibility still sits with the owner even when a mortgage company usually handles the payment through escrow.

The county said second-half 2025 taxes are due by 5 p.m. on May 11, because the normal May 10 deadline falls on a Sunday and rolls to the first business day afterward. Under county rules, second-half taxes are normally due by May 10 and must be paid by that date, or the next business day when May 10 lands on a Sunday, to avoid delinquent charges. The county also mails tax bills on Nov. 1 each year, with first-half taxes due by Nov. 10 and required by Dec. 10 to avoid delinquent charges.

That timing matters for homeowners who pay through escrow and may assume the mortgage company has the bill covered automatically. Los Alamos County says property owners remain responsible for making sure the tax bill is paid. For a homeowner with a $2,000 second-half bill, missing the May 11 deadline would leave the full balance exposed to delinquent charges and the administrative problems that follow a late tax payment.

County payment options include paying in person at the Customer Care Center, paying in person at Enterprise Bank & Trust at 1200 Trinity Drive in Los Alamos, mailing a check or money order to P.O. Box 99 in Los Alamos, using the dropbox at the Municipal Building, or paying online through eNoticesOnline with the authorization code from the most recent tax bill. If a taxpayer does not have that code, the county says to contact the Customer Care Center for help. The Customer Care Center can be reached at 505-662-8333, and the Assessor’s Office lists 505-662-8030 with office hours from 8 a.m. to 5 p.m. Monday through Friday.

The reminder lands in the middle of the county’s annual tax cycle. Assessor George Chandler said Notices of Value were mailed on April 1, 2026, for all property valued for taxation, a separate notice that helps set up the tax bill owners are now being asked to pay on time.