How to respond to job offer letter

Acceptance

Dear (recruiter name)

This is with reference to the offer letter you sent, dated (date).
I would be grateful to accept your offer for the position of (job title) in your organization.

As discussed, my salary would be (x) rising to (x) after the duration of my probationary period.
I will be joining on (date) as detailed in my offer letter. I also accept the terms and policies of the company as detailed in the given offer letter.
Kindly let me know if there are any formalities or documents pending from my end that you would require.
Looking forward to seeing the team soon.

Regards
(Signature)

Counteroffer

A counteroffer is a response given to an original offer. It results in the rejection of the original offer and introduces a new one.

Dear HR

Thank you for your offer for your organization’s (x) position. I feel this position fits my experience, and I would be able to offer a lot.

I am hoping that we can discuss the salary component further.
I have received another offer from (x) company for the amount of (x). I’d like to discuss the opportunity of moving closer to the salary of (x), which I feel would better represent my experience in this field.

Please let me know if you would be interested in discussing this further.

Regards