Sorting a CSV file, but not it's header

I need to sort a CSV file, but the the header row (1st row) keeps getting sorted. This is what I'm using: cat data1.csv | sort -t"|" -k 1 -o data1.csv Here's a sample line: Name|Email|Country|Company|Phone Brent Trujillo|tempus@mauris.org|Burkina Faso|Donec LLC|(612) 943-0167