overstated form 1099

[sj32]

A1099-NEC filed by one of my clients stated they paid me more in 2020 than what I actually received.  I assume it's because they mailed a check to me on December 31 that I received in January.  I report on a cash basis. 

How do I report this on my tax return?  My QuickBooks income shows less than the total 1099-NEC's because I post payments on the day I receive them, not their check date.  

If I use the totals on the 1099-NEC's then I will be filing a higher income than what I received.

If I file the total income that I actually received in 2020, will that be a red flag to the IRS for audit, since the 1099's tell the IRS that I received more income.

[Mike9241]

the easiest way is to report gross then use returns and allowances for amounts not received.  make sure that you actually received it in 2021. I would say that if they mailed payment in December you should have received it by now.