part and parcel

"Parcel" is used in its archaic sense of "an integral or component part." Originally used as a legal term.

part and parcel (usually uncountable, plural parts and parcels)

1. An integral or essential piece; that which must be done or accepted as part of something else.

   Regular maintenance is part and parcel of owning a car.

   • 1998, Wilhelm Geuder, Miriam Butt, The Projection of Arguments, Introduction:

     Argument structure is thus considered to be part and parcel of the information associated with lexical, syntactically atomic verbs.

   • 2016, Allison Moon, “Mapping Your Route: Anatomy & Orgasm”, in Girl Sex 101‎^[1], 2nd edition, Lunatic Ink, →ISBN, →LCCN, →OCLC, page 117:

     It's a great idea to get good at using vibrators both on yourself (if you like them) and on partners. For many women, vibrators are part and parcel of good sex. Sometimes you'll like having unassisted sex for a while and then finish off with a vibrator. Sometimes a vibe can be great to add to penetrative sex.

   • 2019 October 23, Pip Dunn, “The next king of Scotland”, in Rail, page 50:

     On the date of RAIL's train test in early summer, there were just two sets in traffic. Class 170 (or even '158') substitutions were still part and parcel of the daily service, although availability has since improved.

• come with the territory