ワードアップ英会話 WORD UP ENGLISH CLASS | 日記 | Vocabulary: "No problem."

The expression "no problem" is basically a more casual way of saying "thank you," and is very commonly used. In fact, one linguist's Internet research shows that "no problem" is now actually used more than "thank you." It is a very natural and common expression, and in most social situations you can use it freely.

So, for example:

Linda: Thanks for the flowers!
Paul: No problem. I hope you like them!