Permalinks

Hi, I am copying a site to a different domain so I can use the same layout with different content. The instructions I am following say to set permalinks to default, then copy the DB etc. If after doing this, I reset the permalinks to the original custom structure on the original site (the site I am copying) then everything should still work as it originally did on the original site? I am just worried as I see a lot of posts about sites breaking when changing permalink settings. Thanks in advance for any help.

Kind regards,
Suhail