Hey, I actually resigned from my previous law firm (boutique firm)and things ended on a pretty sour note with the Partner, now as that was my first job, I shall be applying to other firms or organisations for the first time as a professional. I wanted to know as proof of my experience I currently have no experience letter or document (unlikely that the Partner would even provide the same), the only piece of evidence/proof is the Salary Account that I had with the firm tbh Lol and the Retainership Letter that I had received. Is this a necessary document that law firms require when they onboard someone through a Lateral hire ?

No, law firms typically don't insist on an experience letter. At best your new firm will hire an external agency to just confirm from the previous firm that you had worked at that firm. If you were a good or a bad actor, depending on the personality of the partner they may provide additional feedback on your performance.

Also, if you dont expect the previous firm to revert, please be transparent about it to your new firm's management so as to set the expectation. Also, ensure that couple of your ex-colleagues can vouch for you and your work (including linkedin reccos).

Things ended on a bad note at my first job and my old boss flat out refused to give me an experience letter. Very disconcerting at the time but soon I realised most lawyers or law firms for that matter don’t care about an experience letter. HR practices are really informal and if someone wants you on their team they don’t look for experience letters.

Another learning no matter how badly you end things time heals all rifts. You ex-boss or you can’t afford to hold grudges. Networking is too important in our profession. A couple of years later when I went in-house my boss very happily gave me an experience letter.