Refuse to Accept: Avoiding Formal Deficiencies in 510(k) Submissions

1. Key takeaways

Refuse to Accept (RTA) is the administrative screening step FDA performs before substantive review begins. Even when the eSTAR template has been used, three classes of formal deficiencies can still cause a submission not to be accepted: inconsistent numbering and references — the K number, product code, registration number, and listing number do not match across the dossier; missing or invalid signature and authorization — the authorization documentation for the submitter is absent or expired; and internal contradictions between sections — the same parameter is given different values in different sections. None of these defects is about the science; all of them are enough to stop the clock before the review of substance even starts, and each of them is detectable in advance with a structured self-check.

• RTA screening is formal in nature, which means it is fully preventable by disciplined self-checking before submission.
• Numbering inconsistencies are the most mechanical failure mode: four classes of identifiers recur throughout the dossier and must match everywhere they appear.
• Authorization documents have validity periods, and a letter that has lapsed between preparation and filing is a classic rejection trigger.
• Cross-section contradictions in values are invisible to template-level automation and must be caught by human cross-proofreading.
• Because the screening is administrative, a documented self-check record is itself part of good submission practice.

2. Legal basis

The screening criteria and the tools that support the submission sit in the instruments listed below, drawn from the source material.

3. Expert insights

Insight one: eSTAR automatic verification solves checks inside the template, not consistency across sections.

The eSTAR page describes its automation as covering form construction, autofill, and automatic verification. Automatic verification can catch empty fields and formatting errors, but it cannot detect a cross-section contradiction such as a sterilization method stated as ethylene oxide in one section and as irradiation in another. Contradictions of this kind live in the meaning of the text, not in the structure of the form, and they are found only by deliberate manual cross-proofreading against a parameter list. Automation reduces one class of defects; it does not reduce the other to zero.

Insight two: the numbering systems must be aligned in a single pass.

A 510(k) dossier involves at least four classes of identifiers: the registration number of the manufacturing establishment, the listing number of the product (or the exempt product code grouping), the K number of the predicate device, and the product code of the device under review. Each of these appears repeatedly throughout the submission, and a single wrong occurrence anywhere is enough to trigger a formal finding. The economical approach is to enumerate every occurrence of every identifier once, in a table, and reconcile the whole set before filing. Treating this as a one-time alignment exercise, rather than a spot fix each time a mismatch surfaces, is what keeps the dossier stable through review.

Insight three: the validity periods of electronic signatures and authorization documents are easily overlooked.

Under 21 CFR Part 11, electronic records and electronic signatures must meet the corresponding requirements. The recurring practical failure is an authorization letter — for example, one in which a foreign company authorizes its US Agent or submitter — that has passed its expiry date, or a signatory whose identity does not match the person named in the authorization document. These are dated documents, and their validity has to be re-checked at the moment of submission, not at the moment they were drafted. A mismatch between the person who actually signs and the person authorized to sign is treated the same way as an expired letter, so both dimensions deserve a line in the pre-filing check.

Insight four: whether eSTAR submissions are exempt from RTA should follow the latest official FDA position (practical estimate).

Sources differ on whether submissions made with eSTAR are exempt from the RTA step. The GRZAN recommendation is to prepare on the assumption that administrative screening still applies, and to spend the time that automatic verification saves on improving the quality of the substantive content rather than on relaxing the formal standard. A submission that would pass a stricter screening also passes a looser one; the reverse is not true, and the cost of the asymmetry falls entirely on the sponsor.

4. Practical recommendations

• Run a full numbering errata pass before submission: list every occurrence of the four classes of identifiers across the entire text and verify them one by one.
• Run a parameter consistency edit: extract every numerical parameter in the dossier — dimensions, doses, shelf life, sterilization parameters, software versions — and compare each across sections.
• Verify the validity period of the authorization documents and the identity of the signatory before submission.
• Use the eSTAR automatic verification for a first self-check, then perform manual cross-proofreading on top of it.
• Keep a record of the formal self-check as a project deliverable.

5. Verification checklist

• □ Registration number, listing number, predicate K number, and product code have been reconciled as consistent across the full text
• □ All numerical parameters have been extracted and compared across sections one by one
• □ The authorization letter is within its validity period and the signatory matches the submitter
• □ Electronic signatures comply with the requirements of 21 CFR Part 11
• □ The eSTAR automatic verification has been passed
• □ The formal self-check record has been archived

Regulatory information verified as of October 28, 2026.

How GRZAN can help. GRZAN provides medical device and IVD registration, quality system, US Agent and local testing support for the United States market. Our team manages FDA establishment registration and listing, 510(k)/De Novo/PMA submissions, and supports post-market reporting obligations. Business enquiries: info@grzanglobal.com