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N354 Remark Code: Incomplete or Invalid Invoice

N354 means the payer received an invoice with the claim but it was incomplete or invalid. It lacked details the payer needs, such as the item, cost, vendor, or date, or it did not match the claim.

Quick facts

Code
N354 (RARC N354)
Status
Active In use since August 1, 2005; last modified March 14, 2014.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The line was denied or held because the supporting invoice could not be used. The provider sends a complete invoice; the patient is not billed.
Official description
Incomplete/invalid invoice.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N354 means

For supplies, implants, and drugs that have no fixed fee, payers often price the line from the provider’s cost. The proof of that cost is the vendor invoice. N354 is used when an invoice arrived but failed review: it was missing key information, was hard to read, or didn’t line up with the claim.

Because an attachment was received but found deficient, N354 frequently pairs with CARC 251. Some payers use CARC 16 or 252 instead.

What makes an invoice incomplete or invalid

  • No item description or catalog number, so the reviewer can’t tie it to the billed code.
  • No unit cost or quantity, or totals that don’t reconcile.
  • Discounts or rebates missing. Many payers want net cost after discounts.
  • Vendor name, date, or invoice number missing.
  • Mismatch with the claim, such as a different quantity, item, or a date far from the service date.
  • Illegible copy or a partial page.

How to fix it

  1. Get a clean copy of the original vendor invoice for the item billed.
  2. Mark the line that matches the claim and confirm the item, quantity, and cost agree with what you billed.
  3. Include any discount, and the patient identifier or claim number the payer asks for on attachments.
  4. Send it through the payer’s attachment process, using the attachment control number on the claim if you submit electronically.
  5. If the payer wants the claim itself corrected too, resubmit with frequency code 7 and the original claim number.

How to prevent it

Save invoices for cost-priced items with the patient’s encounter when the item is used, rather than hunting for them after a denial. A checklist for attachments (vendor, item, quantity, net cost, date, legible) catches most problems before they go out.

Codes that may appear with N354

  • CO-251 (The attachment/other documentation that was received was incomplete or deficient.): The attachment received was incomplete or deficient; N354 says it was the invoice.
  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim lacks information needed to process it, here the pricing support from the invoice.
  • CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): An attachment is required to adjudicate the claim.
  • M23 (Missing invoice.): Used when no invoice was received at all.
  • N446 (Incomplete/invalid document for actual cost or paid amount.): Covers an incomplete or invalid document for actual cost or paid amount.
  • N649 (Payment based on invoice.): Indicates payment was based on the invoice.

N354 FAQ

When do payers ask for an invoice?

Usually for items priced at cost, such as unlisted or not otherwise classified supplies, drugs, implants, and some DME. The invoice shows what the provider paid.

Can I send a quote or order confirmation?

Payers generally want the actual invoice from the vendor showing the purchase. A quote or packing slip usually won't satisfy the request.

Should I black out other items on the invoice?

It is common to highlight the relevant item and redact unrelated patients' information. Keep the vendor, item, cost, and date readable.