The service of a subpoena duces tecum is invalid unless at the time of such service a copy of the affidavit upon which the subpoena is based is served on the person served with the subpoena. In the case of a subpoena duces tecum which requires appearance and the production of matters and things at the taking of a deposition, the subpoena shall not be valid unless a copy of the affidavit upon which the subpoena is based and the designation of the materials to be produced, as set forth in the subpoena, is attached to the notice of taking the deposition served upon each party or its attorney as provided in Chapter 3 (commencing with Section 2002) and in Title 4 (commencing with Section 2016.010). If matters and things are produced pursuant to a subpoena duces tecum in violation of this section, any other party to the action may file a motion for, and the court may grant, an order providing appropriate relief, including, but not limited to, exclusion of the evidence affected by the violation, a retaking of the deposition notwithstanding any other limitation on discovery proceedings, or a continuance. The party causing the subpoena to be served shall retain the original affidavit until final judgment in the action, and shall file the affidavit with the court only upon reasonable request by any party or witness affected thereby. This section does not apply to deposition subpoenas commanding only the production of business records for copying under Article 4 (commencing with Section 2020.410) of Chapter 6 of Title 4.
§ 1987.5.Subpoena duces tecum; conditions to validity; original
Title 3. Of the Production of Evidence · Chapter 2. Means of Production · Last amended 2005 · Last verified July 29, 2026
In one sentenceSection 1987.5 requires anyone serving a subpoena duces tecum to also serve a copy of the affidavit supporting it, extends that same requirement to deposition subpoenas by tying the affidavit and materials list to the deposition notice, and lets an aggrieved party seek relief such as excluding evidence or retaking the deposition when that requirement is violated.
Full Text of § 1987.5
Plain-English Summary
A subpoena duces tecum commands someone to show up with documents or things in hand, and this section makes sure the person on the receiving end knows exactly why they've been asked to produce what's listed. Whoever serves the subpoena has to hand over, at the same time, a copy of the affidavit that justified issuing it in the first place. Skip that step and the service itself doesn't count.
Depositions get an extra layer. When a subpoena duces tecum calls for someone to appear and bring materials to a deposition, the supporting affidavit and the list of what's being sought have to be attached to the deposition notice that goes out to every party or their attorney. If materials show up at a deposition despite that requirement being skipped, the other side isn't left without a remedy: it can move for relief, and the court can exclude the evidence, order the deposition retaken, or grant a continuance. The section also tells the party who served the subpoena to keep the original affidavit until the case reaches final judgment, filing it with the court only if someone asks, and it carves out an exception for subpoenas that ask only for business records to be copied under the Discovery Act's separate records procedure.
Frequently Asked Questions
What happens if a subpoena duces tecum is served without a copy of the supporting affidavit?
The service is invalid. Section 1987.5 makes the affidavit copy a condition of valid service, not an optional courtesy.
Does this affidavit requirement apply to subpoenas for deposition testimony and documents?
Yes. The affidavit, along with a description of what's being sought, must be attached to the deposition notice served on every party or their attorney.
What can a party do if materials were produced without the required affidavit?
File a motion for relief. The court can exclude the evidence, order the deposition retaken, or grant a continuance.
Does this requirement apply to a subpoena asking only for business records?
No. Section 1987.5 exempts deposition subpoenas that command only production of business records for copying under the Discovery Act's separate records procedure.
Amendment History
(Added by Stats.1951, c. 1413, p. 3368, § 1. Amended by Stats.1968, c. 95, p. 1783, § 2; Stats.1981, c. 189, p. 1114, § 1; Stats.1982, c. 452, § 2; Stats.1985, c. 1239, § 1; Stats.1993, c. 926 (A.B.2205), § 7; Stats.2004, c. 182 (A.B.3081), § 20, operative July 1, 2005.)
Source & verification. Section text is reproduced verbatim from
the West's Annotated California Codes / Thomson Reuters. Enacted by the California Legislature.
Last verified July 29, 2026.
· Official source
Also known as: subpoena duces tecum affidavit requirementdeposition subpoena missing affidavit california