What is included in an offer letter? Offer letters include essential employment details, such as a job title, start date, and compensation details.The pay rate in the offer letter is binding for the work he has already done. Basically you're expected to accept an offer and join the work without having any written proof of appointment and confirmed agreement on your payout. Your employment with the Company under this Offer Letter will commence on or around October 11, 2021 (the "Effective Date").