This a question from a friend with no internet access.
Relates to the 03/04 year
Back ground is she was started working for an agencey were the money and hours changed each week. and the contact was monthly, so she had no idea what she was earning. Her old job was v.low paid and got high tax credits from them. (from the 02/03 year P60)
She notifed them of this situation, and they said its ok, just leave it and when they come to this years 04/05 report it will be sorted out.
It turns out when she got hours she was pretty well paid (around 15k a year but only for certain months through the year, no work in summer or over christmas etc) compared to the 4k a year it was worked out at.
In Feb of this year she got a new job again, and told them about it, and that it was for 20k a year. (all of this was done over the phone) and that she had moved house to live with her new partner.
The payments did not change over this time, even though she told them this information. She thought it was strange but since she informed them, she thought it must be correct.
Her new form comes for the 04/05 year and she fills it in, and now today she recived a thing saying they want to investigate the 03/04 claims for the 10k she recived from them over this time till sept.
And she needs to product all sorts of documents for them, bank statements, gas bills, payslips etc
She is worried she will go to jail etc and she owes them a fortune and how will she pay it back. And that they might not have put somthnig into the computer correctly. And it will look like she is trying to rip them off etc.
As it all seems to steam from the wait till your new P60 to sort it out answer, but her wages were very unpredictable, as some months she earned nothing.