MAM-260-B Historical Aircraft Information is the notice the San Diego County Assessor/Recorder/Clerk, Business Division / Marine & Aviation, sends to aircraft owners whose records indicate the aircraft may qualify for the Historical Aircraft Exemption for 2026. It is one of the San Diego County property tax forms for aircraft, and it explains the filing steps, the certificates of attendance and the late-filing rules. On this page you can fill out the form online on FillingPDF and download or print the completed PDF; the original is published by the Assessor at the official URL below.
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What is MAM-260-B?
MAM-260-B Historical Aircraft Information is the San Diego County Assessor/Recorder/Clerk's Marine & Aviation notice for aircraft owners whose aircraft may qualify for the Historical Aircraft Exemption for 2026, explaining what to file, which certificates to attach and the late-filing rules.
The page is headed "Historical Aircraft" and is issued by the Business Division / Marine & Aviation section of the Assessor's Office. It accompanies the exemption claim itself, BOE-260-B, Claim for Exemption from Property Taxes of Aircraft of Historical Significance. The notice tells first-time filers to complete the front of the BOE-260-B (P1) and tells owners who already hold the exemption to list on the back the exact dates the aircraft was displayed in 2025.
It also explains the legal background. Revenue and Taxation Code section 220.5 was amended to require certificates of attendance to be attached to claims, and SB1059 added Revenue and Taxation Code section 276.5, which allows a partial exemption for late filing.
Related Assessor documents are listed together on the Assessor's Historical Aircraft Exemption forms list: BOE-260-B (the claim) and MAM-260-C, Certifications of Attendance for Aircraft of Historical Significance, a form you may duplicate and carry to shows and displays.
Who needs to file MAM-260-B?
Owners of aircraft in San Diego County whose records the Assessor's Office says may qualify for the Historical Aircraft Exemption for 2026 are the audience for this notice. What you do depends on your history with the exemption:
- First-time filers: complete the front of the BOE-260-B (P1) and submit the one-time fee for each aircraft.
- Owners previously granted the exemption: indicate on the back of the BOE-260-B the exact dates the aircraft was displayed in 2025, and submit the required certifications of attendance for the 12 events you attended.
To meet the requirements for the exemption, the aircraft must be displayed at 12 advertised public events during the previous calendar year and must be on display during the entire display period. You must sign the application to state that all information is accurate. The notice names no representative who may sign for you and sets no further exclusions; direct eligibility questions to the Marine and Aviation Section of the Assessor's Office at 858/505-6200.
When to file MAM-260-B
File the Historical Aircraft Exemption application by February 15 to receive a full exemption. If you file between February 16 and August 1 and meet the qualifications, you receive an 80% exemption of the full value of your aircraft, under Revenue and Taxation Code section 276.5.
The certificates of attendance follow the calendar year: for the 2026 filing you submit certificates for the display days you attended during 2025. Certificates collected at shows and displays in 2026 are submitted with your 2027 Historical Aircraft application. The notice sets no other deadline.
Documents you need
- Certification of attendance for each of the 12 display days you attended in 2025, for owners previously granted the exemption; the 2026 filing requires them to be attached.
- Form MAM-260-C, which you may use and duplicate to collect the certifications from each show or display operator.
- Check or money order payable to San Diego County Assessor for the one-time fee, for each aircraft, for first-time filers only.
How to fill out MAM-260-B
Confirm whether you are a first-time filer
Read the notice: first-time filers complete the front of the BOE-260-B (P1), while owners previously granted the exemption complete the display dates on the back.
Complete the front for a first filing
If this is your first filing, fill in the front of the BOE-260-B (P1) for each aircraft.
Enter the 2025 display dates
If you already hold the exemption, indicate on the back of the BOE-260-B the exact dates the aircraft was displayed in 2025.
Gather certificates of attendance
Collect a Certificate of Attendance for each of the 12 display days you attended in 2025. Form MAM-260-C may be used and duplicated for this.
Check the display requirements
Confirm the aircraft was displayed at 12 advertised public events and was available for the entire posted hours of each show.
Sign the application
Sign to indicate that all information is accurate.
Review, download and assemble
Check every entry, then download or print the completed PDF from FillingPDF and assemble the package, with the fee if you are a first-time filer, as described under How to submit.
How to submit MAM-260-B
The notice names no separate delivery channel: it directs you to submit the application and the certificates of attendance to the Assessor's Office. The letterhead identifies the office as the San Diego County Assessor/Recorder/Clerk, Business Division / Marine & Aviation, 9225 Clairemont Mesa Blvd., San Diego, CA 92123-1211, telephone 858/505-6200, fax 858/505-6266.
- First-time filing: send the completed front of the BOE-260-B (P1) with the one-time fee for each aircraft. A fee applies; pay by check or money order payable to San Diego County Assessor, and ask the Marine and Aviation Section at 858/505-6200 for the current amount.
- Previously granted exemption: send the BOE-260-B with the dates of display on the back, signed, together with the certifications of attendance for the 12 events you attended.
Questions about the exemption go to the Marine and Aviation Section of the Assessor's Office at 858/505-6200. FillingPDF lets you fill out and download the PDF; submission follows the Assessor's channels above.
Common mistakes to avoid
- Filing a repeat claim without the certifications of attendance; Revenue and Taxation Code section 220.5 requires them to be attached to the claim.
- Counting events at which the aircraft was not available for the entire posted hours of the show; the aircraft must be on display during the entire display period.
- Submitting fewer than the 12 advertised public events required for the previous calendar year.
- Omitting the exact 2025 display dates on the back of the BOE-260-B when the exemption was previously granted.
- Making a first-time filing without the one-time fee for each aircraft, or making the payment out to the wrong payee instead of San Diego County Assessor.
- Filing after February 15 and expecting a full exemption; between February 16 and August 1 the exemption is 80%.
- Sending the application unsigned; you must sign to state that all information is accurate.
Frequently asked questions
What is MAM-260-B Historical Aircraft Information?
It is the San Diego County Assessor's Marine & Aviation notice for aircraft owners whose aircraft may qualify for the Historical Aircraft Exemption for 2026. It explains how to claim the exemption, the certificates of attendance and the late-filing rules.
What is the deadline for the Historical Aircraft Exemption in San Diego County?
File by February 15 for a full exemption. If you file between February 16 and August 1 and meet the qualifications, you receive an 80% exemption of the full value of your aircraft.
Is there a fee to claim the Historical Aircraft Exemption?
Yes, for first-time filers: a one-time fee for each aircraft, paid by check or money order payable to San Diego County Assessor. Call the Marine and Aviation Section at 858/505-6200 for the current amount.
What certificates of attendance do I need?
If you were previously granted the exemption, you need a Certificate of Attendance for each of the 12 display days you attended in 2025, attached to your 2026 filing. The aircraft must be on display for the entire posted hours of each show.
What is the difference between BOE-260-B and MAM-260-B?
BOE-260-B is the claim for exemption you complete: the front for a first filing, the display dates on the back for repeat filers. MAM-260-B is the Assessor's information notice that explains the requirements, the fee and the late-filing rules.
Where do I find shows and displays to attend?
The notice points to the San Diego County Airports website at http://www.sdcounty.ca.gov/dpw/airports.html, which links to Plane News. Its calendar lists some events, but you are not limited to them; confirm dates and times with the coordinator.
Can I fill out MAM-260-B online?
You can fill out the PDF online on FillingPDF and download or print it. FillingPDF is an independent service and does not file anything with the Assessor; you submit your documents through the Assessor's channels.
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