It doesn’t matter how much paperwork it is, that’s the rule.
If you have a partnership with anyone who is not your spouse, partnership must file a form 1065 tax return. The partnership usually does not pay direct tax, but the 1065 will include preparation of a K-1 statement for each partner, which will report each partner’s share of the income and expenses of the partnership on the partners’ individual tax returns. The partnership should have its own EIN, which either one of the partners can obtain online from the IRS in about 15 minutes. One of the partners must be the “responsible person“ for the EIN, but the EIN would belong to the partnership as a separate business entity.
If the partnership later goes on to file an LLC, that will not change its federal tax treatment. LLC‘s are state entities, and the IRS will still consider you a partnership and you will still file a form 1065 for the partnership. Whether your partnership would benefit from an LLC would be a matter for state law and for an attorney to help you with. It is not necessary to create an LLC in order to have a partnership under federal tax law.
Also note that the partnership tax return form 1065 is due March 15, not April 15, and the late fees are substantial. You can request an extension for the 1065, but the request must be filed before March 15.
