It's not clear whether you are the borrower or the lender. You talk about holding the mortgage, and also about sending a form to the mortgagee. Both terms, "hold a mortgage" and "mortgagee," refer to the lender. The person who holds the mortgage is the mortgagee. But you would not send a form to yourself.
If you are the lender, you are required to give a Form 1098 to the borrower for interest of $600 or more, only if you are in the business of making mortgage loans. You only send Form 1098 for interest that you received "in the course of your trade or business." If it's a one-time deal you are not required to send Form 1098. In any case, no version of TurboTax for any year can create a Form 1098. You can report the interest income that you received on your tax return using any version of TurboTax except Free Edition.
If you are the borrower you do not have to create any extra forms. Claiming a deduction for the mortgage interest that you paid depends on whether the mortgage is a seller-financed loan. If it is a seller-financed loan you can claim the deduction in TurboTax Online Deluxe or Premium. If it is not a seller-financed loan there is no way to enter the deduction correctly in TurboTax Online. (This was true for 2024 and earlier, and I expect that it will be true for 2025 as well.) You would have to use the desktop TurboTax software to claim the deduction because it can only be entered in forms mode, which is not available in TurboTax Online.
In all cases it makes no difference whether the borrower and lender are related or not.
TurboTax for 2025 is not yet available, so this information is subject to change when we can see the actual software, but it has been the same for many years so I do not expect any changes.
