ACH Validator
Stop sending broken ACH files to your bank. Upload, validate, fix — in seconds.
Drop a file — we'll check it against NACHA rules in seconds.
Errors, warnings, and file statistics — typically in under two seconds.
5 of 5 free validations remaining this month
Drag and drop your ACH file here
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Supported formats: .txt, .ach (Max 1MB) Files are validated in memory and never saved.This tool is provided as-is for informational purposes only and does not constitute financial or legal advice. Validation results do not guarantee NACHA compliance or acceptance by financial institutions. CodeWright LLC is not liable for damages arising from reliance on validation results. Use is subject to our Terms of Service.
Why Validate Before You Submit?
The cost of finding out later is higher than you think.
Rejected Files
A single broken record can cause your bank to return the entire file. One bad entry delays every payment in the batch.
Missed Effective Dates
Errors caught after submission mean angry recipients, resubmitted batches, and effective dates you can't recover.
ODFI Relationships
Repeat rejections put your standing with your originating bank at risk. Clean files keep the relationship healthy.
Instant File Validation
Drag and drop your ACH file. Get comprehensive validation results in seconds — formatting, data integrity, and NACHA compliance checked end-to-end.
- Supports .txt and .ach files up to 1MB
- Results in seconds — no waiting, no queues
- Detailed error reporting with line numbers
- Files are never saved — validated in memory only
Errors That Explain Themselves
Most validators say “Record 6, field 3 invalid.” Ours tells you “Trace Number at line 12, position 79: missing check digit.” You see what's wrong, where it is, and how to fix it.
- Errors: critical issues that will cause rejection
- Warnings: potential problems worth reviewing
- Info: best practice suggestions
- Messages grouped by location — fix a whole batch at once, not one field at a time
Field-Level Precision
Other tools point at a line. We highlight the exact character range of the offending field — so you know precisely which 10 characters need attention, not which 94.
- Click a message to jump to the line and see the field highlighted
- Every NACHA field labeled — Amount, Trace Number, Routing, and more
- Hover the highlight to see the full field name
- Works across header, entry, addenda, and control records
File Content Preview
See your file alongside the results. Line-numbered, severity-colored, and one click away from any problem area.
- Color-coded lines by severity — errors red, warnings yellow, info blue
- Line numbers for easy reference and communication with your team
- Click any error message to jump to the exact line
- Dark or light code viewer — toggle to your preference
- Copy file content to clipboard with one click
File Statistics at a Glance
Every validation run gives you a one-screen snapshot of what's in the file — so you catch the wrong file, wrong date, or wrong origin before you dig into the entries.
- Batch count, entry count, and addenda totals
- Total debits and total credits, formatted for readability
- Immediate origin and destination routing — plus resolved bank names
- File creation date and time in local format
Catch What Basic Validators Miss
Format checks are table stakes. The issues that actually get files rejected are the ones most validators skip.
- Duplicate detection — same trace number, amount, and routing flagged across the file
- Balanced file — verify debits equal credits before your ODFI does
- SEC code rules — PPD, CCD, WEB, TEL, and more each validated against their own requirements
- Addenda validation — addenda records checked against SEC-specific rules
- Large amount threshold — configurable warnings on outlier entries to catch data-entry mistakes
Validate on Your Terms
Not every file needs the same checks. Toggle validation options to match your workflow — whether you need strict NACHA compliance or a quick format check.
- Enforce full NACHA spec compliance or allow common shortcuts
- Verify routing numbers with the ABA check-digit algorithm
- Flag entries with effective dates outside acceptable windows
- Adjust options before each upload — no configuration files to edit
- Re-validate the same file with different options — no need to re-upload
Built for Audit and Compliance
Validation isn't just about catching errors — it's about proving you caught them. Every run can produce a durable record for your compliance team or your auditor.
- Export JSON — machine-readable results for automated pipelines and archives
- Print results — clean, formatted output for paper trails and audit packets
- Severity breakdown — errors, warnings, and info at a glance for review sign-off
- Nothing saved server-side — your data stays on your side of the wire
What We Validate
Comprehensive checks across all ACH record types
File Structure
Record counts, blocking factors, and file organization
Batch Headers
Company information, SEC codes, and effective dates
Entry Details
Account numbers, routing numbers, and transaction codes
Control Totals
Hash totals, debit/credit balancing, and entry counts
For Banks & ODFIs
Community banks embed this validator into their commercial banking portal — branded as their bank's service — to validate customer-submitted files before ACH processing.
Fewer returns. Better customer experience. A new recurring revenue line you couldn't previously offer. The embeddable widget runs entirely in your customers' browsers — file data never transits FiSTWorks infrastructure, which substantially narrows the scope of vendor evaluation.
Learn More About Bank PartnershipsSee What's Wrong Before Your Bank Does
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