Thanks @JBedford!
This independent contractor job is my sole job - full time - so I don't have withholding for myself for any other work.
To clarify - I need to use our joint income and tax liability from 2022, multiply by the 110% as we are over $150k to get the total estimated tax amount for this year, subtract what is being withheld by my spouse's employer, then divide that remainder by 4 for each quarter to get my personal estimated tax responsibility.
Am I understanding that correctly?
