お邪魔します

Etymology
Compound of.

Phrase

 * 1) hello, sorry for any trouble

Usage notes
Said upon arrival when visiting someone's place. Literally means “I'm being a bother,” “I'm bothering you,” in recognition of the likelihood that the visit puts some burden on the visitee, such as taking up their time.

At the end of the visit, upon departing, the visitor may say, “I've been a bother” → “thank you for your time.”