your seller has not shipped the goods yet. if you just got the number, wait about 7 days and track it in http://track-chinapost.com/startairmail.php. If your seller really shipped the goods, it will show tracking result within 7 days. Otherwise it will show invalid number.

Quote from garethgunit on May 3, 2016, 21:16
hello can you please help me..?
my tracking number is RI856459457CN
i have heard nothing in a month from tracking can you give me any information on my parcel?

1. This is the full tracking of your parcel to UK:
Parcel No.RI856459457CN tracking result
2016-03-23 16:41:21.0 佛山city Post Office parcel 集邮局 received
2016-03-23 19:01:38.0 佛山city Post Office parcel 集邮局 customs scan
2016-03-23 22:15:57.0 leaving 佛山city Post Office parcel 集邮局 ，next station 佛山
2016-03-24 12:43:18.0 Guangzhou Transit Station export security scan
2016-03-24 13:43:41.0 Guangzhou Transit Station export customs cleared
2016-03-25 10:08:00.0 arrive Guangzhou Airport
2016-03-25 13:27:58.0 leaving Guangzhou Airport going to next airport/seaport
2016-03-27 12:29:00.0 Guangzhou departure
2016-03-29 09:44:00.0 arrive Guangzhou Airport
2016-03-29 12:09:54.0 leaving Guangzhou Airport going to next airport/seaport
2016-03-31 09:14:00.0 arrive Guangzhou Airport
2016-04-02 13:18:00.0 arrive UK Langley Transit Station
2016-04-06 10:31:04.0 leaving Guangzhou Airport going to next airport/seaport

2. I suspect your parcel tried a couple of time to flight out of China but was not able to (no room for the mail bag). Then suddenly it arrive in UK:
2016-04-02 13:18:00.0 arrive UK Langley Transit Station

3. Then again it is leaving Guangzhou Airport:
2016-04-06 10:31:04.0 leaving Guangzhou Airport going to next airport/seaport

4. I suspect there was a mistake in Langley Transit Station and the mail bag was ship back to China. But China Post discover the mistake and ship the mail bag back to UK.

5. Please contact your seller and maybe copy and paste the above tracking and ask him to call China Post to find out exactly what happen to your parcel.

6. You might want to read this for UK:
China Post Airmail Parcel Estimate Arrival Time
On this site:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

7. Again please contact seller to have him call China Post : 86 20 11185

Hope this help.