Need your help reviewing a uk post office receipt

[pothos]

I have a troublemaker that is giving me a lot of issues.
This person is from UK and gave me a uk post office mailing receipt and said the product was returned but I didn't get any package.
I am trying to look for the tracking number on the receipt but couldn't find one.

I am from Canada and not familiar with uk post office.
Can someone from uk please pm me to let me know you can look at this receipt?
Thank you.

[james_112233]

It will either have a tracking number or it won't in which case you can not track/trace it.

The number will be under the word BARCODE or where it simply says REFERENCE NUMBER.

You can put that into www.royalmail.com/track-trace

[pothos]

This receipt doesn't have a barcode or reference number.
Do people need to pay extra to buy tracking number in uk?

[JamesNorth101]

They do yes. It’s not standard in the U.K.