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R26 - Mandatory Field Error

A field that the Nacha format requires to be populated is missing or contains erroneous data. The entry is structurally incomplete.

R26 - Mandatory Field Error

A field that the Nacha format requires to be populated is missing or contains erroneous data. The entry is structurally incomplete. This rejection is recoverable: correct the cause and the same payment can be resubmitted.

Data & formatACH · NACHA (US) Recoverable
Can you resubmit? This rejection is recoverable: correct the cause and the same payment can be resubmitted.

What this code means

A field that the Nacha format requires to be populated is missing or contains erroneous data. The entry is structurally incomplete.

Typical causes

  • Required field left blank by the originating system
  • Field padded incorrectly in the fixed-width 94-character record
  • Mandatory field populated with spaces or zeros where a value is required

What to do

Populate the missing mandatory field and re-send. Not a reinitiation.

What it looks like in an ACH return

The return arrives as an Addenda Record (type 99), 94 characters wide. The return reason code sits in positions 4-6.

799R26091000010000001      09100001                                            091000019000001

Tools for this code

Decode a real status report, or check a payment file before you send it — all in your browser, nothing uploaded.

Related codes

ACH return codes: the complete reference

Source: Nacha ISO 20022 mapping guide + Federal Reserve ACH Return Reason Report + US Treasury Green Book · Last verified: 2026-07-13

Checked against: nacha.org · frbservices.org

All rejection codes