I have a client, tax payer and spouse both live in NY until March 01, and both has income only source of NY state income. They moved to NJ from March 01 and until Dec 31, 2023. Both tax payer and spouse W2 did not property allocated resident period and non resident period.

For NY state they show full, city shoes only two months and NJ show 10 months during resident period.

When I did part year resident of NY and income source from NY, NY calculate tax on all income sources from NY. 

When I did NJ tax return for part year, they calculate their tax based on resident period of income they received from new York from March 02 to December 31, 2023. NJ also calculating tax on that period. and no credit coming up on income they paid taxes on New York. It's look like double tax. Is it correct?

NJ not computing any tax credit that client paid in NY?

I don't think my client will double tax for same income for both the states? I am using ProSeries Professional.

Please give idea from your practical experience and as per law on this situation.