I'm nothing near a tax expert, so please forgive me for asking the following question in detailed layperson's terms.
Given the following situation....
- I'm self-employed (sole proprietor, with no employees), have been for years, and will be through at least 12/1/2015.
- On 4/1/2015, I created a SEP-IRA, retroactive effective date 1/1/2014.
- On 4/1/2015, I made my entire 2014 tax year contributions to the SEP-IRA, retroactively.
- Have made no contributions to the SEP-IRA that would appear on my 2015 tax return.
- On 8/1/2015, create a Solo-401k, effective retroactively to 1/1/2015. (Note that the SEP-IRA intended for 2014 contributions wasn't even created, in real calendar dates, until after the retroactive effective date of the Solo-401k intended for 2015 contributions.)
- After Solo-401k is created, and before end of real year, make 2015 Solo-401k contributions, based on income for the entire 2015 year (i.e., since the 1/1/2015 effective date of Solo-401k, not only since the 8/1/2015 real date that the Solo-401k was created).