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What is a DMF letter of authorization?
A DMF letter of authorization permits FDA to refer to specified master-file information in support of another party’s submission. Identify the holder, DMF, authorized party, covered material and responsible execution, then coordinate holder-side submission and the relying party’s copy. The letter is not an agent appointment or proof of DMF approval.
Before you begin
Authorization to reference a human-drug master file. This is not a device master-file letter, an ESG authorization or a general appointment of an agent.
What you will prepare: A scoped authorization letter and coordinated holder/applicant handoff ready for review.
Identify who grants the authorization and what it covers
A DMF letter of authorization permits FDA to reference specified master-file information in support of another submission. Start by distinguishing the holder granting permission from the applicant or sponsor relying on it. The letter should make the authorized information and the authorized party identifiable.
This is not the same document as an agent appointment or an authorization used for an electronic gateway account. FDA's template index lists the DMF letter of authorization and agent appointment separately. If someone asks for an “authorization letter,” establish the purpose before selecting a template.
Practical starting question: which information does this application need FDA to reference, and who controls the permission? If the master file, holder or relying party is uncertain, resolve that relationship before drafting.
Collect the identifiers and the scope of reference
Section V of FDA's DMF guideline describes the authorization elements: date, holder, DMF number, authorized party, covered products, relevant submission dates, referenced sections/pages, a holder commitment, and the authorizing official's signature, name and title. Use the current template alongside that guidance.
Build a working record of those details and their owners. Be precise about what material is covered; an unclear reference forces the recipient to guess which version or portion the letter intends. Ask the holder to resolve scope that the applicant cannot verify from its own records.
The applicant does not need to rewrite confidential DMF content into the letter. Keep the purpose focused on permission and identification. Do not imply that receiving the letter itself gives the applicant access to all confidential information in the master file.
Use an outline that makes the permission easy to review
Editorial working outline, to be reconciled with the FDA template:
- Identify the letter, its date and the DMF reference.
- Identify the holder and the party receiving the right to reference.
- Describe the products and information covered, with the relevant references.
- Include the appropriate holder commitment and authorized execution.
- Identify who will coordinate the holder-side submission and applicant-side copy.
Keep internal reviewer notes out of the executed letter. Before the final copy is produced, have both sides confirm the legal names and scope. If a placeholder remains, return it to its owner rather than using a broad phrase to conceal missing information.
The outline is a writing aid. The authority to grant the reference and the truth of a holder commitment must come from the actual responsible party.
Coordinate both sides of the handoff
FDA's guideline describes holder-side authorization and a copy for the applicant, sponsor or other holder incorporating the information by reference. Treat these as coordinated tasks, not one email attachment sent without a filing owner.
Use current FDA submission resources to establish the applicable electronic procedure. The historical guideline also contains paper-copy and physical-delivery instructions; do not turn those into current eCTD instructions. The letter's content and the method of delivering it are separate questions.
Recommended handoff record: final letter version, confirmed identifiers, intended referenced material, holder-side owner, applicant-side owner and evidence that each assigned action was completed. This is an operational record, not a claim that FDA has reviewed or accepted the referenced material.
Worked review: the letter names the wrong legal entity
Fictional editorial exercise: the holder prepares the authorization using a development partner's name. The relying application is being filed by a different legal entity after a transaction.
Before assuming the permission covers the applicant, compare the authorization with the current applicant record. Ask the holder and responsible regulatory/legal reviewers to resolve whether a corrected authorization is needed. Preserve the explanation and final decision in the handoff record.
A familiar trade name or a corporate relationship does not answer the permission question by itself. The useful review outcome is an unambiguous match between the actual authorization and the intended reliance. This example illustrates a review method; it is not a legal conclusion about a particular corporate transaction.
Reconcile the permission on both sides of the reference
Use a handoff map to keep permission, information identity and filing responsibilities connected.
| Relationship | Confirm with the responsible owner | Common ambiguity |
|---|---|---|
| Holder to DMF | Legal holder and exact master-file number | A supplier trade name substitutes for the holder |
| Permission to relying party | Named party and relevant application context | A corporate affiliate is assumed to be covered |
| Scope to information | Products, sections and relevant submission references | The applicant cannot identify which material is authorized |
| Letter to holder submission | Executed version and assigned action | Applicant has a copy but holder-side action is unconfirmed |
| Copy to relying application | Matching version and reference | Different scope appears in the application narrative |
Handoff exercise: the holder sends a revised authorization, but the relying application still cites the prior letter. Compare scope and legal identities before replacing files. Determine which version supports the intended reliance, then reconcile the letter, reference narrative and delivery records together.
Use the FDA template index for the actual letter elements and distinguish content from the current electronic procedure. Historical paper-copy instructions should not be republished as current eCTD directions.
Compare the authorization with the marketing form or IND form, as appropriate. Shared application identifiers help trace the reference; they do not themselves grant permission.
Your preparation checklist
0/5 checkedUse this to track your review in this visit. Checks are not saved and do not establish regulatory compliance.
Frequently asked questions
Does an LOA give the applicant all confidential DMF content?
No. The authorization allows FDA to reference the identified information for the supported submission. It is not automatically a grant of access to all confidential master-file contents. Keep permission and information disclosure distinct when preparing the letter and the applicant’s records.
Is a DMF LOA the same as appointing an agent?
No. FDA lists the letter of authorization and agent appointment as separate templates. One concerns reliance on master-file information; the other concerns representation or contact responsibilities. Establish the intended purpose before drafting a generically requested authorization letter.
Does receiving an LOA mean FDA has approved the DMF?
No. FDA explains that DMFs are not independently approved or disapproved; their technical contents are reviewed in connection with the supported application. An authorization establishes a permission relationship, not a finding that the referenced evidence is adequate or accepted.
Sources and revisions
Requirements, source recommendations and editorial preparation advice have different roles. Review the scope and revision of the source you use.
Guidance
FDA Guideline for Drug Master Files, section V ↗1989 guideline, section V on authorization. Historical paper-delivery instructions elsewhere are not used as current electronic-filing advice.
FDA resource
FDA DMF templates ↗Current template index includes letter of authorization, withdrawal of LOA and agent appointment as distinct documents.
FDA resource
FDA Drug Master Files resources ↗Current submission resources; use these to establish the applicable electronic submission procedure.
Technical specification · placement only
FDA eCTD v4.0 comprehensive hierarchy ↗Version 2.2, February 2025. Section 1.4.1. A heading identifies placement, not mandatory applicability.