Our credit card department requires 3 months proof of income for underwriting. This is mainly because in this area tourism is the main employer so many people work part-time jobs or don't consistently make the same wages each week. They feel three months will allow them to better estimate annual income.

When an applicant cannot produce 3 months proof of income for a job, then that income is not used in the income analysis. They are using 'unable to verify income' as the decline reason. But this doesn't seem correct since they did verify the income, just not for as much time as they wanted. I may be over thinking it.

So, would 'unable to verify income' be ok to use? Should we use 'other" and say something like 'insufficient proof of income'?

I would use "insufficient length of employment" or "temporary or irregular employment."