I've just had a debt from barclays passed to Moorcroft "to collect on their behalf". My default dropped off my file last month. what Unclebulgaria67 says is correct in that the debt can't be put back on your credit file.
I'll be following this thread with interest. I wish your brother good luck.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!