NachaTech - ACH File Editing and Validation Software

Overview

What is a NACHA file?

The NACHA File Format is a standard format specified by National Automated Clearing House Association (NACHA) to facilitate capturing debit or credit transactions against bank accounts.

Who uses the NACHA file format?

Financial institutions that need to perform monetary transactions, such as paying bills, crediting or depositing money, typically use the NACHA standard. Those transactions are typically performed against bank accounts for individuals or organizations.

The NACHA standard captures these transactions in a consistent and standard manner.

Billions of transactions are performed using the NACHA standard every year.

Why use the NACHA file format?

The NACHA format allows for the standardization of transactions across banks and financial institutions. This standardization allows for the seamless processing of transactions and better security of sensitive information.

Automated Clearing House (ACH) has become the go-to network for B2B transactions and moves billions of transactions a year.

The NACHA File Format

A NACHA file prompts ACH payments to be made based on the content in the various records. The format of a NACHA file includes a text file using 94 characters per line. The file supports ASCII characters.

Each line in a NACHA file is called a record. The structure of the file includes five different record types. Those record types are:

File Header
Batch Header
Detail
Addenda (optional)
Batch Control
File Control

A record type is identified by the starting character for each line.

Record Type	Starting Character
File Header Record	1
Batch Header Record	5
Detail Record	6
Addenda Record	7
Batch Control Record	8
File Control Record	9

The file layout is as follows:

File Header Record
- Batch Header Record
  - Detail Records
    - Addenda (Optional)
- Batch Control Record
File Control Record

Important Information about NACHA format

A single NACHA file can contain multiple batches.
Each batch can contain multiple transactions (detail records).
Each transaction can have an optional Addenda record.
Batch Control provides a summary of the batch.
The File Control record provides a summary of the file.

Record Types

File Header

The File Header presents information such as the payer of the transaction as well as the financial institution administering the transaction.

#	Field	Type	Required	Start	End	Length	Fixed Value	Format Mask	Regex
1	Record Type Code	Digits	YES	1	1	1	1		^1$
2	Priority Code	Digits	YES	2	3	2	01		^01$
3	Immediate Destination	Alphanumeric	YES	4	13	9		bNNNNNNNNNN
4	Immediate Origin	Digits	YES	14	23	10		1NNNNNNNNNN NNNNNNNNNN
5	File Creation Date	Date	YES	24	29	6		YYMMDD
6	File Creation Time	Time	YES	30	33	4		HHMM
7	File ID Modifier	Alphanumeric	YES	34	34	1
8	Record Size	Digits	YES	35	37	3	094		^094$
9	Blocking Factor	Digits	YES	38	39	2
10	Format Code	Digits	YES	40	40	1	1		^1$
11	Immediate Destination Name	Alphanumeric	YES	41	63	23
12	Immediate Origin Name	Alphanumeric	NO	64	86	23
13	Reference Code	Alphanumeric	NO	87	94	8	blank spaces

Batch Header

As opposed to the File Header, the Batch Header presents more detailed information regarding the payment such as the standard entry class, payment descriptions, effective entry date, and various other prenotes.

#	Field	Type	Required	Start	End	Length	Fixed Value	Format Mask	Regex
1	Record Type Code	Digit	YES	1	1	1	5		^5$
2	Service Class Code	Digits	YES	2	4	3			^2(?:00\|2[05])$
3	Company Name	Alphanumeric	YES	5	20	16
4	Company Discretionary Data		NO	21	40	20	Blank
5	Company ID	Digits	YES	41	50	10
6	SEC Code	Characters	YES	51	53	3
7	Company Entry Description	Alphanumeric	YES	54	63	10
8	Company Descriptive Date	Alphanumeric or YYMMDD	NO	64	69	6
9	Effective Entry Date	Date	YES	70	75	6		YYMMDD
10	Reserved			76	78	3	Blank
11	Originator Status Code		YES	79	79	1	1		^1$
12	Originating DFI ID	Numeric	YES	80	87	8
13	Batch Number	Numeric	YES	88	94	7

SEC Codes

Here are the SEC codes and their brief description.

ARC

Accounts Receivable Entries

BOC

Back Office Conversion

CCD

Corporate Credit or Debit

COR

CIE

Customer Initiated Entries

CTX

Corporate Trade Exchange

IAT

Internation ACH Transmission

POP

Point of Purchase

POS

Point of Sale

PPD

Pre-arranged Payment or Deposit

RCK

Represented Check Entries

TEL

Telephone Initiated Entries

WEB

Internet/Mobile Initiated Entries

Detail Record (Transaction)

The Detail Record (Transaction) includes the data which is needed for a deposit or withdrawal from a bank account. The information included could be a recipient’s name, the specific dollar amount of the transaction, or the account number of either party.

#	Field	Type	Required	Start	End	Length	Fixed Value	Format Mask	Regex
1	Record Type Code	Digits	YES	1	1	1	6		^6$
2	Transaction Code	Digits	YES	2	3	2			^01$
3	RDFI ID	Digits	YES	4	11	8
4	Check Digit	Digit	YES	12	12	1			^[0-9]$
5	DFI Account Number	Alphanumeric	YES	13	29	17
6	Amount	Digits	YES	30	39	10		$$$$$$$$¢¢
7	Identification Number	Alphanumeric	NO	40	54	15
8	Receiving Company Name	Alphanumeric	YES	55	76	22
9	Discretionary Data	Alphanumeric	NO	77	78	2
10	Addenda Record Indicator	Digits	YES	79	79	1	0 or 1		^[0\|1]$
11	Trace Number	Digits	YES	80	94	15

Addenda

The addenda record contains additional information regarding the payment in the NACHA file. Most commonly used for business to business transactions, the addenda could include information such as supplemental information that could be required to identify the holder of the account or even just an opportunity to convey important information

Batch Control

The Batch Control record simply includes the total amount of all entries in the batch.

#	Field	Type	Required	Start	End	Length	Fixed Value	Regex
1	Record Type Code	Digit	YES	1	1	1	8	^8$
2	Service Class Code	Digit	YES	2	4	3		^2(?:00\|80\|2[05])$
3	Transaction and Addenda Count	Digit	YES	5	10	6
4	Entry Hash	Digit	YES	11	20	10
5	Total Debit	Digit	YES	21	32	12
6	Total Credit	Digit	YES	33	44	12
7	Company Identification	Digit	YES	45	54	10
8	Message Authentication Code	Alphanumeric	NO	55	73	19	Leave blank
9	Reserved	Alphanumeric	NO	74	79	6	Leave blank
10	Originating DFI ID	Digit	YES	80	87	8
11	Batch Number	Digit	YES	88	94	7

Hash Value for Batch Control

The sum of the value(s) in the receiving DFI identification (field 3, positions 4-11) for every entry detail record (6) in the file.

If the sum exceeds 10 characters, the field must be populated with the rightmost 10 characters. To get the rightmost characters, do modulo 10000000000L

File Control

The File Control Record acts as a final review on the data submitted. It contains the count of all records, the count of entries, as well as debit and credit totals.

#	Field	Type	Required	Start	End	Length	Fixed Value	Regex
1	Record Type Code	Digit	YES	1	1	1	9	^9$
2	Batch Count	Digit	YES	2	7	6
3	Block Count	Digit	YES	8	13	6
4	Entry/Addenda Count	Digit	YES	14	21	8
5	Entry Hash	Digit	YES	22	31	10
6	Total Debit	Digit	YES	32	43	12
7	Total Credit	Digit	YES	32	43	12
8	Reserved	Alphanumeric	YES	56	94	39	Blank spaces

Hash Value for File Control

The entry hash is the sum of the entry hash fields contained within the batch control records of the file. (e.g. sum of all field 4 of eight (8) records in the field).