> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trackstarhq.com/llms.txt
> Use this file to discover all available pages before exploring further.
# USPS
> Sample invoice CSV for USPS, pulled from the Enterprise Payment System (EPS) transaction report.
## Overview
USPS delivers invoice data as EPS transaction reports — one row per postage transaction. Each row represents a single charge (label purchase, refund, scan form, etc.), so shipments and line items are 1:1 in this CSV (unlike UPS or FedEx, which have multi-row shipments).
## Shape notes
* **One row per transaction.** Unlike other carriers where a single shipment produces multiple rows, USPS EPS emits one row per event — a label purchase is one row, a subsequent refund is a separate row with a negative `Transaction Amount`.
* **Transaction types vary.** Common values include `Label Purchase`, `Label Refund`, `SCAN Form Used`, `Carrier Pickup`, and `Shipping Services File`. The `Transaction Type` column becomes the `charge_description` in the Trackstar-normalized output.
* **Dates are space-separated.** `Transaction Date/Time` uses `YYYY-MM-DD HH:MM:SS` format.
* **Tracking numbers are IMpb barcodes.** The `Package Identification Code (PIC)` column holds the 20–22 digit USPS IMpb barcode, which Trackstar maps to `tracking_number`.
* **Pass-through fields.** Trackstar uses only 5 columns (`PIC`, `EPS Account #`, `EPS Transaction ID`, `Postage`, `Transaction Date/Time`, `Transaction Type`). The remaining 15 columns pass through in the `raw` field.
## Sample rows
The full CSV is shown here because USPS has only 21 columns. The downloadable CSV contains additional rows.
```csv theme={null}
ACH Withdrawal ID,ACH Withdrawal Amount,EPS Account #,EPS Transaction ID,Transaction Amount,Transaction Date/Time,Transaction Type,EFN,Package Identification Code (PIC),Mail Class,Postage,CRID,Master MID,Permit Number,Permit Type,Permit Finance Number,Reason,Details,Cust Ref Num1,Cust Ref Num2,Dispute ID
600126146287812131,23.54,2684030563,6258250725712,23.72,2026-03-01 00:44:00,SCAN Form Used,78040954577960076935,4335647197791615280044,Priority Mail,23.72,196946120,936725700,869390,PI,696447412,,,ORD-000000,,
798745740698154416,6.70,2684030563,2930981279092,6.34,2026-03-01 07:45:00,Label Purchase,31328393343983579206,2763541425546063107612,First-Class Package Service,6.34,196946120,936725700,869390,IMI,417176062,,,ORD-000001,,
397285208437793537,17.73,2684030563,9448598755437,18.05,2026-03-01 14:58:00,SCAN Form Used,46622006836046155654,6220271650671714456685,Parcel Select Ground,18.05,196946120,936725700,869390,OMAS,123073776,,,ORD-000002,,
912361099971760982,26.20,2684030563,3616825412233,27.88,2026-03-01 21:00:00,Carrier Pickup,81431220160867147962,0219491151180344381731,USPS Ground Advantage,27.88,196946120,936725700,869390,IMI,238232735,,,ORD-000003,,
303971003922821593,28.12,2684030563,1107793877784,25.80,2026-03-02 04:09:00,Label Refund,11765625298377889577,2296049909992957912190,USPS Ground Advantage,25.80,196946120,936725700,869390,PI,051456075,Customer Request,,ORD-000004,,
```
## Download
Download full sample CSV (25 rows, 21 columns)
All sample data is synthetic. Tracking numbers, account numbers, addresses, and reference fields are fabricated and do not correspond to any real shipments or customers.
## Fields
| Column | Description | Example | Parsed |
| :---------------------------------- | :----------------------------------------------------------------------------- | :----------------------- | :----: |
| `ACH Withdrawal ID` | Bank withdrawal reference | `600126146287812131` | |
| `ACH Withdrawal Amount` | Amount withdrawn via ACH | `23.54` | |
| `EPS Account #` | Enterprise Payment System account — mapped to `account_id` | `2684030563` | ✓ |
| `EPS Transaction ID` | Unique transaction ID — mapped to `invoice_id` | `6258250725712` | ✓ |
| `Transaction Amount` | Total debited | `23.72` | |
| `Transaction Date/Time` | `YYYY-MM-DD HH:MM:SS` — mapped to `transaction_date` | `2026-03-01 00:44:00` | ✓ |
| `Transaction Type` | Type of transaction — becomes `charge_description` | `Label Purchase` | ✓ |
| `EFN` | Electronic File Number | `78040954577960076935` | |
| `Package Identification Code (PIC)` | USPS IMpb tracking number — mapped to `tracking_number` and the line-item `id` | `4335647197791615280044` | ✓ |
| `Mail Class` | Service class | `Priority Mail` | |
| `Postage` | Postage amount — mapped to both `gross_cost` and `net_cost` | `23.72` | ✓ |
| `CRID` | Customer Registration ID | `196946120` | |
| `Master MID` | Master Mailer ID | `936725700` | |
| `Permit Number` | Permit imprint number | `869390` | |
| `Permit Type` | Permit type (`IMI`, `OMAS`, `PI`) | `PI` | |
| `Permit Finance Number` | Finance number on the permit | `696447412` | |
| `Reason` | Reason (e.g. for refunds) | `Customer Request` | |
| `Details` | Additional transaction details | | |
| `Cust Ref Num1` / `Cust Ref Num2` | Customer-supplied references | `ORD-000000` | |
| `Dispute ID` | Dispute case reference | | |
Columns marked ✓ are parsed into the Trackstar `invoice_line_items` schema; the rest are preserved in the `raw` field.