I have been selected as a software Engineer in a company X and I have accepted the offer letter. After few days I got selected in company Y they are paying higher than company X but company X is very good and I still want to join company X only. My question is can I renegotiate salary from company X by showing the offer of company Y. Is it ethical to renegotiate the salary of accepted offer? Suppose If I join company X, will the salary renegotiation create any kind of bad impression in that company?
If you have already clicked 'Accept' on the company's website, I would strongly discourage trying to renegotiate the salary.
HR typically uses the candidate's acceptance to initiate the rest of the joining process. If you now go back to renegotiate the salary, they will have to restart the process, which is highly irritating. In the extreme case, they would withdraw the offer, but more likely, they will simply refuse to increase the salary offer. Now you have gained nothing from the adventure, but created a bad impression for yourself, even before you signed the papers.
Company X agreed to offer you a certain salary based on their assessment of your skills, experience, etc. and also, based on how much they were capable of paying you. Have any of those parameters significantly changed in the past few weeks warranting them to reconsider how much they pay you? Unlikely.
My question is can I renegotiate salary from company X by showing the offer of company Y.
You could certainly try, but that approach has risks. You are basically going back on your word. Many hiring managers (like me) wouldn't be happy that shortly after you agreed to one set of terms, you are now trying to change them.
In some situations, the hiring manager can simply withdraw the offer. You could ruin your chances of working for company X, and for working with the hiring manager ever again.
Is it ethical to renegotiate the salary of accepted offer?
Your personal ethics are unique to you, and something you must decide for yourself. It's certainly not something I would ever do, or advise my friends and family to do. But your mileage may vary.
Suppose If I join company X, will the salary renegotiation create any kind of bad impression in that company?
Quite possibly, yes.
As I indicated, you are telling your new employer that they cannot trust you to stand behind what you say (not to mention what you signed). That's not an impression I'd want to leave with my company.
For me, trust is extremely important, as is my reputation.
If you accepted the offer, and then a few days later they called you and said, "You know, we've decided we really can't afford to pay you that much, we have to reduce the offer by 10%", I think you'd have very bad feelings about that company, regardless of where you went from there. It works both ways. Trying to change the terms of a contract after you've signed it is at best rude and technically illegal.
Something I figured out along the way in life: When you're considering taking a new job, making a major purchase, or any other sort of "big contract", make reasonable efforts to get the best deal you can, and then once you've made your decision and signed on the dotted line, DON'T KEEP SHOPPING. Don't even look at any other offers or possibilities that may come up. Because unless you got the best possible deal in the entire world, then there's a better deal out there somewhere. And if you keep looking, sooner or later you'll find a better deal. But as it's now too late, you're already committed, the only thing that knowing about the better deal does is make you dissatisfied and unhappy with the deal you made.