The U.S. Department of Commerce (DOC) has admitted errors in its tariff calculations on two truck and bus tire manufacturers in China, and as a result has lowered the rates Double Coin Holdings Ltd. and Guizhou Tyre Co. Ltd. — and all companies — will pay.

In all, the DOC made seven errors.

Both companies submitted complaints alleging the errors after the DOC announced its final tariff rates on Jan. 23.

After fixing these errors, the DOC says Double Coin’s tariff rate is decreasing from 38.61% to 20.98%. The rate for Guizhou is dropping slightly, from 65.46% to 63.34%.

Making adjustments to those specific companies also affects the rate charged to all other companies — from 52.04% to 42.16%.

The details

Here’s what happened with the Double Coin calculation. The first mistake was a basic subtraction error. The second error was in applying a currency exchange rate to an amount that had already been converted.

The Guizhou calculations are a bit more complex. One mistake stemmed from how the intercompany sales from one Guizhou subsidy were accounted for. Another error came in linking to the wrong table of data. The wrong benchmark for electricity rates at two facilities was used in calculations. The DOC also admitted it used a 2004 sales figure in a calculation compared to benefits received in 2015. And in the fifth and final error connected to Guizhou calculations, the DOC says it should have entered the actual price paid for land in one table, but instead entered benchmark prices.