The core bit error rate of the USB medium is expected to be close to that of a backplane and any glitches will very likely be transient in nature. To provide protection against such transients, each packet includes error protection fields. When data integrity is required, such as with lossless data devices, an error recovery procedure may be invoked in hardware or software.

The protocol includes separate CRCs for control and data fields of each packet. A failed CRC is considered to indicate a corrupted packet. The CRC gives 100% coverage on single- and double-bit errors.