Form 424B3 BLACKROCK MUNIHOLDINGS

Filed Pursuant to Rule 424(b)(3)

Registration File No.: 333-288713

BLACKROCK CALIFORNIA MUNICIPAL INCOME TRUST

BLACKROCK MUNIHOLDINGS CALIFORNIA QUALITY FUND, INC.

Important Information Regarding the Joint Proxy Statement/Prospectus, dated September 4, 2025 for BlackRock California Municipal Income Trust (“BFZ”) and BlackRock MuniHoldings California Quality Fund, Inc. (“MUC” or the “Acquiring Fund”)

The following changes are made to the Joint Proxy Statement/Prospectus:

The Section of the Joint Proxy Statement/Prospectus entitled “Voting Information and Requirements – Voting Requirement for Proposal 2: The Issuance of Acquiring Fund Common Shares” is deleted in its entirety and replaced with the following information:

Voting Requirement for Proposal 2: The Issuance of Acquiring Fund Common Shares

All other references in the Joint Proxy Statement/Prospectus and the accompanying exhibits referencing the vote requirement for shareholders to approve Proposal 2 are hereby revised and restated to reflect the vote requirement stated in the table above.