The country had insisted shipments of materials for recycling would be turned away from September 1 unless they had a registration number.
The Far Eastern nation exerts such influence on the market that when it stopped importing to clear its ports earlier this year, global metal prices collapsed.
So the huge importer of metal, plastic and paper has been inundated with companies trying to register under the new rules.
But only half of the received forms have been processed by the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), according to the Bureau of International Recycling (BIR).
A statement released by BIR this week said: So far AQSIQ has received more than 3,500 applications, half of which have already been processed.
Temporary registrations have been granted to the accepted applicants pending the issuance of an official registration number.
In September, AQSIQ will send five delegates to visit the plants of some of the applicants (two in Europe, one in the US, one in Japan and one in Australia). It is expected that all registration numbers should be issued by the beginning of October.
To gain a registration number, firms must satisfy AQSIQ they have a company business licence and conform to criteria including certain industry standards.
The consensus among UK merchants was that it was taking around five weeks to complete registration, with one putting the cost at just over £3,000.
China introduced the registration system after becoming fed up with the number of substandard loads it received from abroad.
Some UK merchants blamed shoddy practitioners within the industry, while others claimed China was just buying itself time to clear metal it had over-ordered.
BIR members send around 60% of the metal scrap and recovered paper that China imports each year, as well as huge volumes of recyclable plastic.