He didn't make estimated payment for 2022 instead, his AGI was 215k with taxes withheld of 39k which created refund of 2k. 

What amount of AGI is considered high income individuals that pay 110% of their tax? 

Even 110% of taxes applies, this is where I was thrown off:

His total tax is $37171 vs total payment of $39413, they got refund. How should I explain to my client why they still need to pay ES payment when they don't owe taxes after the total tax is lesser than total payment. 

Or the total tax being withheld is supposed to be 37171x110% = $40881 by law which is greater than the total payment of $39413, which generates dues of $1475. That's why each ES payment is 1475/4= $369

In fact, after netting the total refund of $2242 and ES payment, he only gets $776 (2242-1475) refund. 

Does it sound right? 

Thank you

Mona