State tax filing
Based on your question, it would appear you are using TurboTax Desktop to enter your data and file your return. The screens below correspond to the items you are referring to:
Line 4b for your 2021 Tax:
The software does indeed allow you to enter the amount that was showing on Line 49 of your NJ-1040 2021 return. Entering the correct number here, even if overriding what TurboTax brought forward, will not affect your guarantee for accuracy as most manual entries would. It presupposes that perhaps the latest version of what you filed was not showing in TurboTax or you did not use TurboTax in the prior year and therefore, allows you to enter a manual entry. Just be certain it is the actual number from the return that was filed.
Line 15, shown below, is to enter the tax shown on Line 49 and what you previously entered on Line 4b above. This is to calculate any exclusion you may be entitled to to avoid an underpayment penalty. If you wish to annualize, that option is also available but simply entering the amount where indicated on Line 15 would suffice to avoid the penalty.
The link you refer to is fairly plain. Not being able to see your return, if your current year withholding and/or payments equals 110% of last year's tax then the safe harbor NJ refers to is met and no penalty would be assessed. However, as the rule goes on to say, the Division of Taxation will impose estimated tax penalties and interest on an underpayment of estimated tax only on the difference between what was actually paid and either 100% of last year’s tax or 80% of the current year’s tax. Chances are, and this is without being able to see your actual return, that you would qualify for the safe harbor under one of the above rules.
