Is it mandatory to join a company after accepting the offer letter?

Is it mandatory to join a company after accepting the offer letter, especially when someone has got the interview through referral and cracked it.
If no, then how to convey it to the recruiter in a good way?

20mo ago

JumpyUnicorn

Stealth

20mo

Hello Abc,

Unfortunately I won't be joining xyz organisation. Thanks for the opportunity, would love to be with xyz org in the future. Sorry for the inconvenience. Regards, OP

WobblyMarshmallow

Walmart

20mo

Hey, I know the email format.

I was thinking, if someone has got the interview through referral and has cracked it, and later don't join. Will it have a bad impression on the person who has given the referral, and his future referral might not hold value?