When one party accepts the other party's offer or counteroffer, including communicating that acceptance to the offering party, a purchase contract is created. A counter offer letter is a physical letter or email candidates send to an employer when they want to negotiate the terms of a job offer given to them.Step 5: Follow the format. A counter offer must be done in a specific format which includes an introduction, a body and a conclusion. How do I fill out the Counter Offer Form? A wellwritten counteroffer letter is professional, concise and courteous. Your goal is to negotiate politely and reasonably with your potential new employer. Composing a powerful counter deal letter is a basic interaction that can assist you with landing the position you need for the pay bundle you think you merit. This is a tutorial all about counter offers. There are three different counter offers that we're going to take a look at and I'm going to talk you through them.