use Modern::Perl;
use Data::Dumper;

my $text= join '', <DATA>;

my %customers;

$customers{$_}++ for $text =~ m/{(.*?)}/g;

say Dumper(\%customers);

__DATA__
AB1\tA{Daniel Wright}\sA{Jack Smith}\sB{Jane Goodwin}
QW1\tA{Samantha Patton}\sC{Timothy Eeckles}
AR2\tA{Jane Goodwin}