On a recent question, 非回答者さん wrote the following comment:
Tokyoites say ごめんください all the time when entering another person's home. I cannot even think of another phrase that could replace it.
Another user was surprised and asked a follow-up question on chat:
Don't people use お邪魔します too when entering another people's house?
They do seem rather similar, so I thought I would ask about them here: