Invoice reimbursement

[PS]

Hi, 

I'm looking for some information on Invoice reimbursement, generally the balance in the forfeiture can be used to pay invoice and re-allocate to participants or even make employer contribution.  Incase the Plan does not have invoice and they want to use the funds in the forfeiture to reimburse a pervious invoice that they paid I believe they can do it however  should this be within 1 year of the payment or can it be anything up to 5-6 years?

In reviewing the plan document I'm unable to find any information not sure if the plan document talks about this. 

Thanks