Hey @Nicholas Morgan!
I think with residential property, a pre approval letter is a must.
You can verbally/ informally commit to a selling price while negotiations are ongoing and they might not ask you to produce proof of funds at that time. However in order to lock it down and prevent others from having access to the sale, you have to submit a contract and usually a pre approval letter.
These arent that difficult to obtain if you have a descent income and credit score. Infact, some banks offer online pre-qualification letters you can apply for and then use for any properties you are interested in.
I used USAA and Suntrust to get preapproval letters before I started shopping, just to make my self look more legitimate while negotiating.
As for commercial- It is a catch 22 like some have said above. You just have to keep contacting lenders until you find one that you "jam" nicely with and they can provide you with a letter so long as you have proof of funds.
Lastly, if you have friends that are interested in investing, I think just verbally having people commit depends on how strong your relationships are with them. I am ok with verbal commitments with about 3 people in this world.
Life can happen and people who have verbally committed might not be able to follow through- leaving you in a last minute hustle to find replacement funds. Not to mention potentially shake those relationships.
One mroe thing, theres something about finding a great deal that almost forces you to find the money to secure it.
So even if you dont have it locked down now, dont let that prohibit you from going on the hunt. When its a great deal, the money usually follows in this business.
Good luck!