How do I find my total tax liability from prior year for estimated payments?

The specific lines you're looking for depend on which forms you filed, but I can point you in the right direction! For federal taxes, look at your Form 1040 from last year - your total tax liability is on Line 24 (Total Tax). That's the number you'd use to calculate the 110% safe harbor provision for federal estimated tax payments. For California, check your Form 540 - look for the line labeled "Total Tax" (usually line 64 on the 2023 form). For Illinois, it would be on your IL-1040, again looking for the "Total Tax" line. Once you have these numbers, multiply each by 1.1 (110%) and compare to your current withholdings. If your current withholdings will meet or exceed these amounts by the end of the year, you're good to go. If not, you might need to make estimated payments or adjust your withholding.

I was in a similar situation last year with multiple state taxes and a mid-year move. I was pulling my hair out trying to figure out all these calculations until I found this tool called taxr.ai (https://taxr.ai). It seriously saved me so much time! I just uploaded my prior year returns, and it highlighted all the important lines I needed for calculating safe harbor amounts for both federal and state taxes. It even helped me figure out the proportional state tax calculations since I had moved mid-year. Might be worth checking out if you're still feeling overwhelmed.

Just wanted to follow up about taxr.ai since I ended up trying it. Holy crap, it's actually incredible for multi-state tax situations! I uploaded my returns and it immediately showed me exactly what I needed for the 110% calculation for both federal and state taxes. It even created a withholding calculator to help me figure out if I'm on track for the current year. The document analysis was way more thorough than I expected - it pulled out all kinds of useful information I didn't even know to look for. Definitely recommend it if you're dealing with a move between states or just want to double-check your calculations.

If you're having trouble reaching the IRS to get specific guidance on your situation (which is likely - I tried calling them 8 times last month), I'd recommend using Claimyr (https://claimyr.com). They can get you connected to an actual IRS representative without the typical 2+ hour wait. Check out their demo at https://youtu.be/_kiP6q8DX5c - it shows exactly how it works. I was dealing with a complicated estimated tax payment situation with my small business last year and needed clarification on some specific rules. Claimyr got me through to someone who actually knew what they were talking about in about 15 minutes.

I need to publicly eat my words about Claimyr. I decided to try it yesterday because I was desperate to get some answers about my estimated tax payments after moving states mid-year. I assumed it wouldn't work, but they got me through to an IRS tax specialist in about 45 minutes (which is insanely fast compared to my previous attempts). I didn't have to sit on hold at all - just got a call when they had someone on the line. The IRS agent walked me through exactly how to calculate my 110% safe harbor amount across multiple states and confirmed I was on the right track. Saved me from potentially making a big mistake with my quarterly payments. Not gonna lie, I'm impressed.

Just want to add one thing that helped me when I was trying to figure out estimated taxes after moving: the IRS Publication 505 explains the whole 110% safe harbor thing in detail. There's a worksheet in there that walks you through the calculation step by step. It's dense reading but it spelled out exactly what I needed to do.

Just a quick heads up - be careful with state estimated tax requirements. They don't always match federal rules exactly. I got caught with this in IL last year. For Illinois specifically, they require you to pay 100% of your prior year tax liability or 90% of current year, not the 110% that federal uses for higher income folks. I found this out the hard way and ended up with a small penalty.

Thanks everyone for all the helpful advice! I ended up finding the numbers I needed on my tax returns using Paolo's guidance about the specific line numbers. Just wanted to share what I learned in case it helps anyone else in a similar situation: For my move from CA to IL, I had to calculate the safe harbor amounts separately for each jurisdiction. My federal total tax from Line 24 of Form 1040 was $8,200, so I need to pay at least $9,020 (110% since my AGI was over $150k). For California, my prior year liability was $3,100, and for Illinois I'll need to figure out what 100% of this year's expected liability will be since I'm a new resident. The tricky part was realizing that since I moved mid-year, I need to do a partial year calculation for both states. California wants their percentage based on the income I earned while living there, and Illinois wants theirs based on income earned as an IL resident. Going to double-check my math with a tax professional, but at least now I know what numbers to focus on. Really appreciate this community!

This is such a helpful thread! I'm dealing with a similar multi-state situation myself - moved from Texas to Colorado mid-year and have been scratching my head over estimated payments. One thing I learned that might help others: if you're moving from a no-income-tax state (like Texas, Florida, etc.) to a state with income tax, you obviously won't have a "prior year state tax liability" to use for the safe harbor calculation. In that case, you'll need to estimate your current year state tax liability and pay 90% of that amount quarterly, or just make sure your withholding covers it. Also, don't forget that some states have different quarterly due dates than the federal ones! Colorado's are the same as federal, but I know some states differ. Worth double-checking your new state's specific requirements. The taxr.ai tool mentioned earlier sounds really useful for these complex situations. Might give it a try myself since manually tracking all these calculations across jurisdictions is giving me a headache!

I'm dealing with a somewhat similar situation but with a twist - I moved from New York to Florida mid-year, so I'm going from a high-tax state to a no-income-tax state. For anyone else in this reverse situation, here's what I learned: You still need to file a part-year NY return for the income you earned while living there, and you'll need to make estimated payments to NY if your withholding won't cover the liability for that partial year period. The tricky part is that your employer's payroll system might not automatically adjust your state withholding when you move, especially if they're based in your old state. I had to specifically request that they stop withholding NY state taxes once I established Florida residency. One thing that really helped me was keeping detailed records of my move date, utility transfers, voter registration changes, etc. NY can be pretty aggressive about claiming you're still a resident for tax purposes, so having a clear paper trail of when you actually relocated is crucial. Also, don't forget about the potential AMT implications if you had significant state tax deductions in your prior year federal return but won't have them going forward. Worth running the numbers to see if that affects your federal estimated payment calculations too.

This thread has been incredibly helpful for understanding multi-state tax situations! I'm actually dealing with a DC to Virginia move this year and was completely lost on how to handle the estimated payments. One thing I wanted to add that I learned from my tax preparer: if you're moving between states that have reciprocity agreements, it can simplify things quite a bit. For example, DC and Virginia have an agreement where you only pay income tax to your state of residence, not where you work. So if you live in VA but work in DC, you only owe VA taxes (though you still need to file in both places). This doesn't apply to everyone's situation here, but it's worth checking if your states have any reciprocity agreements before you start doing all the complex multi-state calculations. Could save you some headaches! Also, for anyone using tax software, make sure it's designed to handle part-year resident returns properly. I made the mistake of using basic software last year and it didn't handle the income allocation correctly between jurisdictions. Ended up having to file amendments which was a nightmare.