@Frabs , the plan must be established under the partnership and the contribution percentage of all partners must be the same. You cannot independently contribute to any employer plan with the partnership self-employment income. You can us the self-employment income to support a regular IRA contribution to your personal IRA.
https://www.irs.gov/retirement-plans/retirement-plans-faqs-regarding-seps#:~:text=Can%20each%20partn....
