Not reasonably accessible
Not reasonably accessible is the Rule 26(b)(2)(B) category of electronically stored information a party need not produce because retrieving it would impose undue burden or cost, typically backup tapes, decommissioned systems and fragmented or deleted data. The source must still be identified, the burden must be shown, and a court can order production anyway on good cause.
Also called: Rule 26(b)(2)(B) · inaccessible sources · two-tier discovery · cost-shifting · undue burden
Updated September 9, 2026
How does the not reasonably accessible exception work?
Rule 26(b)(2)(B) creates a two-tier structure. The first tier is everything reasonably accessible, which is produced in the ordinary way. The second tier is sources a party identifies as not reasonably accessible because of undue burden or cost, which are not produced unless the court says otherwise.
The rule sets out the sequence plainly. A party “need not provide discovery of electronically stored information from sources that the party identifies as not reasonably accessible because of undue burden or cost.” On a motion to compel or for a protective order, “the party from whom discovery is sought must show that the information is not reasonably accessible because of undue burden or cost.” If that showing is made, “the court may nonetheless order discovery from such sources if the requesting party shows good cause”, and “the court may specify conditions for the discovery.”
Three obligations survive the designation, and they are the ones parties forget. The source must be identified, not silently omitted, which means the responding party has to know what it has. The burden must be shown with specifics: what the source is, what retrieval would involve, what it would cost. And the data must still be preserved while the question is open, because the accessibility rule speaks to production and the litigation hold speaks to destruction.
Conditions attached under the last sentence are where cost allocation happens, alongside sampling: courts frequently order a small restoration first to test whether the source holds anything worth the full expense.
What does a not reasonably accessible source look like?
The same data, on two sides of the line:
| Source | Tier | Why |
|---|---|---|
| Live Microsoft 365 mailboxes, 900 GB | Accessible | Searchable in place; volume is a proportionality question |
| Archived matter in cold storage | Usually accessible | Retrieval is an automated restore, priced but not burdensome |
| Disaster-recovery tapes, 400 tapes | Commonly not | Written for restoration, not search; each restored before it can be read |
| Decommissioned ERP with no running instance | Commonly not | Requires rebuilding an environment to read the data at all |
Illustrative. The designation turns on what retrieval actually involves in the specific case, which is why the showing is evidence rather than a label.
How does an inaccessible source show up on an invoice?
Inaccessible sources are expensive precisely because they sit outside the normal pipeline. Restoring backup tapes is billed as forensic or collection work at hourly rates before a single gigabyte reaches processing, and the restored data then runs through the standard per-GB meters on top.
Archiving is the adjacent line and the one to read carefully. The Fee Field Guide flags providers that charge a monthly archiving fee and a separate reactivation or rehydration fee to bring a dormant matter back, which monetizes the same dormant data twice.
Worth asking: what does archival storage cost per gigabyte, what does reactivation cost and how long does it take, and what would a sampling restoration of a single tape cost, since that figure is often what settles the motion.
Sources
- Fed. R. Civ. P. 26(b)(2)(B), quoted, and the 2006 Advisory Committee Notes introducing the two-tier structure.
- Fed. R. Civ. P. 26(b)(1) on proportionality, which the accessibility analysis sits alongside.
- Zubulake v. UBS Warburg LLC, 217 F.R.D. 309 (S.D.N.Y. 2003) (Zubulake I), on accessibility and cost-shifting.
- The Sedona Conference, Glossary: eDiscovery & Digital Information Management.
- Fee structure: the Fee Field Guide dataset.
Related terms
Proportionality · Litigation hold · Spoliation · Collection · ESI protocol · Meet and confer
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Common questions
What counts as not reasonably accessible?
The rule sets a standard rather than a list, and the test is the burden of retrieval, not the age or obscurity of the source. Disaster-recovery backup tapes written for restoration rather than search are the standard example, along with data on decommissioned or legacy systems and deleted material recoverable only through forensic reconstruction. Data sitting in a live mail system is accessible even if there is a great deal of it, because volume is a proportionality question rather than an accessibility one.
Does calling a source inaccessible excuse preserving it?
No, and conflating the two is the expensive mistake. Rule 26(b)(2)(B) limits the obligation to produce. The duty to preserve is separate, and a source a party expects to argue about is exactly the source it must not allow to be overwritten while the argument runs. Losing it converts a manageable accessibility dispute into a spoliation motion under Rule 37(e).
What is cost-shifting?
An order that the requesting party bear some or all of the cost of retrieving inaccessible data. Rule 26(b)(2)(B) allows the court to specify conditions when it orders discovery from such a source, and cost allocation is the usual condition. Zubulake v. UBS Warburg set out a seven-factor test for when shifting is appropriate that courts still cite, though it applies only once a source is found to be inaccessible.