Overpayment of State Retirement Pension

I’m assisting a Client who has an overpayment of Pension Credit and also State Retirement Pension.

The reasons provided in the statement of reasons for the state retirement pension is that the overpayment was as a result of an undeclared occupational pension.

The pension credit overpayment is correct, however, I cannot understand how an undeclared private pension could affect the amount of state retirement pension someone can receive.

Has anyone else come across this or shed any light on how a private pension would affect the amount of State pension received?

If it helps, the Pension Credit is being recovered from an overpayment period of 8 years,  the state pension is just 9 months.

Thanks

It may be relevant to a contracted-out deduction for state second pension, if DWP was not aware that she was indeed contracted out - but frankly that seems unlikely.

Actually found out that it was minimum income guarantee in the pre pension credit days, mystery solved, I think….

Now that makes sense.