I wish others a happy holiday, and others will reply by SMS. Thank you. Do I need to reply?

Wishing each other a happy holiday is a greeting and concern for each other. The other person's reply to "thank you" is a polite reply to himself, which means to thank you for your greetings, while "you're welcome" is mostly used when you help others or do something beneficial to them. So you don't have to reply in this context.

Extended data:

Precautions for using "You're welcome":

1. When you give or provide convenience and favor to others, or help others to do something, others will thank you.

2. After accepting others' thanks, I usually show some modesty to others' thanks, and add some words to persuade others not to thank them, so as to thank them.

3, generally used to answer you're welcome. Or when you help others, be responsible for what they say when they thank you.