In general, a rollover of retirement funds, such as an IRA or 401(k) Plan, to a Solo 401k plan is a tax-free distribution to the taxpayer from one retirement account (traditional IRA or employer’s pension plan) that rolls over into a similar retirement account within 60 days.
Form 1099-R will be issued to the taxpayer by the financial institution, which transferred the retirement funds to the new Solo 401(k) Plan account. If it was a direct rollover by the institution to another institution, box 7 will contain code G and the rollover will not be subject to tax.
You will receive a copy of the IRS Form 1099-R, which was filed with the IRS. A Copy of the IRS Form 1099-R should be provided to the CPA or tax professional that is filing your income tax return. The amount of the rollover would be reported on IRS Form 1040, line 15a. To show that it is a qualified rollover and none of the amount is taxable, one would enter zero on Form 1040, line 15b, and write Rollover next to line 15b.
Please contact a CPA or tax professional for additional information on reporting rollovers to a Solo 401(k) Plan.