Diamond Bar voters will decide on a proposed 1% sales tax Nov. 3

Diamond Bar voters will decide Nov. 3 whether to approve a proposed 1% local transactions-and-use tax that the city projects could generate about $6 million annually.

The tax has not been approved. On July 21, the Diamond Bar City Council adopted Resolution No. 2026-28, placing the question on the November ballot. The action authorized voters to decide the issue; it did not immediately raise the city’s sales-tax rate.

Why the city is proposing the measure

City officials describe the proposal as a response to a structural General Fund deficit, with ongoing expenses exceeding ongoing revenues. The city’s staff report says projected shortfalls and pressure on reserves have followed earlier spending reductions and other efforts to control costs.

The approximately $6 million figure is a city projection, not guaranteed revenue. If approved, the money would remain locally controlled and could support public safety, Sheriff protection, emergency and wildfire preparedness, street and pothole repairs, parks, recreation and other general city services, according to city materials.

The proposal would create additional unrestricted General Fund revenue rather than a dedicated tax fund. Spending decisions would continue through the city’s regular public budget process.

How the sales-tax rate would change

Diamond Bar’s combined sales-tax rate is currently 9.75%, according to the city’s voter explainer. A separate countywide measure, Measure ER, is scheduled to raise the rate to 10.25% on Oct. 1, 2026, regardless of what happens with the Diamond Bar proposal.

If local voters approve the proposed 1% measure, the city says the combined rate would rise again to 11.25% on April 1, 2027. The countywide Measure ER increase and the proposed Diamond Bar tax are separate actions with separate revenue purposes.

Accountability provisions and voting threshold

Passage requires a simple majority, or 50% plus one of the votes cast on the question. City materials describe annual independent audits, public reporting and oversight through the regular budget process as accountability provisions.

The city’s materials also describe potential exemptions for some common necessities, but voters should rely on the final ordinance and official impartial analysis for the formal details of what would and would not be taxable.

What happens next

Written ballot arguments and the City Attorney’s impartial analysis are due to the City Clerk by 5 p.m. Aug. 14. Rebuttals are due Aug. 24. Those documents are expected to give voters more information about the city’s financial claims, the proposed uses of the money and arguments for and against the measure before the Nov. 3 election.

For now, the local tax remains undecided. The July council action put the question before voters, while the countywide Measure ER increase is scheduled to take effect first on Oct. 1.

Sources

• Diamond Bar City Council staff report and Resolution No. 2026-28
• LAist Measure ER election coverage