A coding error let miss $22.6M in underpaid postage
Summary
The Postal Service built the Automated Package Verification system to catch shippers who underpay — since 2017 it has collected an extra $1.1 billion. Then a routine software upgrade renamed the machines that do most of the weighing, and nobody added the new name to APV's list of trusted machines. For three months in 2026, APV silently dropped 30 to 50 million scans a week. Its own inspector general estimates the Postal Service failed to detect $22.6 million in underpaid postage and $6.1 million in overpayments — and found no monitoring process that would have caught the change.
A workhorse machine, renamed out of the system
The machine at fault is the Automated Parcel Bundle Sorter -- no bit player. It handled about 49 percent⧉ of packages at processing facilities from October through December 2025 and produced about 62 percent of the weights APV trusts. Starting in September 2025, software upgrades renamed the machine to APBS across 's data systems, accelerating in late February 2026. Nobody added the new name to APV's trusted-machine list, so the system simply stopped receiving its scans.
View data as table
| Trusted weights produced by APBS | 62% |
|---|---|
| Packages processed by APBS (Oct–Dec 2025) | 49% |
| Trusted dimensions produced by APBS | 18% |
What three blind months cost
Starting in March 2026⧉, APV lost 30 to 50 million scans a week -- the busiest machines in the network, feeding nothing into the tool built to price them. estimates failed to detect $22.6 million⧉ in underpaid postage and $6.1 million in overpayments it never flagged to refund, over March through May -- a combined $28.7 million mispriced. fixed the coding in June 2026; projects the fix will recover roughly $96.9 million in revenue and $36.6 million in refunds through February 2027. Total monetary impact across the episode: $162,211,620.
View data as table
| Underpaid postage not collected | 22,600,000 |
|---|---|
| Overpaid postage not refunded | 6,100,000 |
Told in March, unfixed in May
notified the Engineering and APV Development teams⧉ in a March 2026 meeting; developers said they hadn't known about the name change. By a May meeting, contractors admitted it still wasn't fixed -- a repair they called a simple coding change. had no process to alert staff to a sudden drop in scan volume, and contractors said they had none that would catch it unless someone told them.
The takeaway
- A rename, not a rewrite, broke the system. No code failed — a machine's name changed and was never added to APV's trusted-machine list, and that alone dropped 30 to 50 million scans a week out of the tool built to catch underpaid postage.
- Most of the evidence went missing at once. The absent APBS machines produced about 62 percent of 's trusted package weights, so the blind spot covered most of the system's weight data — not a corner of it.
- Nothing was watching the watcher. estimates failed to detect $22.6 million in underpaid and $6.1 million in overpaid postage in three months, and found no monitoring process that would have flagged the change; management agreed and set a January 31, 2027 target to build one.
This is a management alert issued during 's ongoing 'Effectiveness of Package Verification Solutions' audit, not the final audit report; says it will address contractor-oversight issues in the full report. The $22.6 million underpaid and $6.1 million overpaid figures are estimates of postage the Postal Service failed to detect from March through May 2026; the $96.9 million and $36.6 million figures are forward-looking estimates of revenue and refunds the June 2026 fix is expected to enable through February 2027. Management agreed with the finding, the monetary impact, and both recommendations, and reported the trusted-machine fix already complete. This piece names no individual; the finding is systemic.
Sources(3) ▾
- U.S. Postal Service Office of Inspector General, Technical Errors Caused Revenue Loss (Management Alert, Report Number 25-130-2-R26) (2026-07-29) — management alert issued during its ongoing 'Effectiveness of Package Verification Solutions' audit (Project Number 25-130). It documents a machine-name change that dropped the Automated Parcel Bundle Sorter (APBS) out of the Automated Package Verification (APV) system's list of trusted machines from March through May 2026, and 's estimate of the resulting uncollected and unrefunded postage. Read in full via the issuer-hosted PDF with pdftotext -layout. Every load-bearing figure below is quoted from the unredacted Results section. uspsoig.gov · original document
- U.S. Postal Service Office of Inspector General, Technical Errors Caused Revenue Loss — report summary and recommendations (2026-07-29) — Issuer-hosted report summary page for management alert 25-130-2-R26. Carries the report's recommendation table, including the stated total monetary impact for Recommendation 1 ($162,211,620) and $0 for Recommendation 2, plus the background figures ($1.1 billion since 2017; ~49% of packages; ~62% of trusted weights). uspsoig.gov · original document
- Council of the Inspectors General on Integrity and Efficiency (oversight.gov), Technical Errors Caused Revenue Loss — CIGIE oversight.gov listing (2026-07-29) — Independent federal-government mirror of the same management alert on a separate host, used as corroboration. Confirms the report number, July 29, 2026 date, issuing agency, the APV/APBS systems, and the background figures ($1.1 billion since 2017, ~49% of packages, ~62% of trusted weights). oversight.gov · original document
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's Automated Package Verification system checks shippers' declared weights against what machines actually measure, then bills or refunds the difference⧉ -- it's collected an extra $1.1 billion since 2017. A July 29, 2026 OIG management alert⧉ found a routine software upgrade broke it: the machines producing most of 's trusted weights got renamed, the new name was never added to APV's trusted-machine list, and for three months the system missed 30 to 50 million scans a week. estimates failed to detect $22.6 million in underpaid postage and $6.1 million in overpayments as a result.