The General Administration of Quality Supervision, Inspection and Quarantine of China (AQSIQ) has published a second list of approved exporters.
The authority simultaneously announced that firms who applied before August 2004 and were not on the latest list would receive a notice of disqualification.
China introduced the registration system in 2004, saying it had become fed up with the number of substandard loads it received from abroad. Some UK merchants claimed China was buying itself time to clear metal it had over-ordered.
Around 3,500 applications had been received by the Asian country when the deadline for exporting without registration passed on September 1.
Companies must now satisfy AQSIQ they have a company business licence and conform to certain criteria, including certain industry standards.
The consensus among UK merchants last year was that it was taking around five weeks to complete registration, with one putting the cost at just over £3,000.
Rejected businesses will not be able to re-apply for registration until six months after they receive their notice of disqualification.
All firms on the list will receive their registration certificates in the post. The list is available at www.bir.org.