APAD:in for a penny, in for a pound

in for a penny, in for a pound

Etymology

Originally with reference to the fact that if one owed a penny, one might as well owe a pound (pound sterling, UK currency) as the penalties for non-payment were virtually identical in severity.

Proverb

in for a penny, in for a pound

Having started something, one must see it through to its end, rather than stopping short; one must “go the whole hog”.

• 1964, Sanki Ichikawa, The Kenkyusha Dictionary of Current English Idioms, page 509:

  …in for a penny, in for a pound: if one undertakes something, it must be carried through at whatever cost.