my %table = ( 
   1 => sub{ ...}, 
   7 => sub {...}, 
   526970 => sub {...}, 
   771770 => sub {...}, 
   ...    
);

use strict; 
use warnings; 
my ($custid, $date, $esid, $amount, $currency, $ppcl_id); 
 
# Use lexical filehandles. 
open my $US_BACKFILL, '>', 'usfile.txt' or die "$!"; 
open my $CA_BACKFILL, '>', 'cafile.txt' or die "$!"; 
open my $BR_BACKFILL, '>', 'brfile.txt' or die "$!"; 
 
my $BACKFILL = $ppcl_id ==      1 ? $US_BACKFILL 
             : $ppcl_id ==      7 ? $CA_BACKFILL 
             : $ppcl_id == 526970 ? $BR_BACKFILL 
             :                      undef 
             ; 
if (defined $BACKFILL) { 
   print {$BACKFILL} "$custid|$date|391|$esid|-$amount|$currency|$ppcl_id|8\n ";  
}

my %BACKFILL; 
 
open $BACKFILL{1}, '>', 'US_backfill.txt' or die "failed to open 'US_BACKFILL.txt' $!"; 
open $BACKFILL{6}, '>', 'JP_BACKFIll.txt' or die "failed to open 'JP_BACKFILL.txt' $!"; 
open $BACKFILL{7}, '>', 'CA_backfill.txt' or die "failed to open 'CA_BACKFILL.txt' $!"; 
 
# the braces around the filehandle are required in this case 
print {$BACKFILL{$ppcl_id}} "$custid|$date|391|$esid|-$amount|$currency|$ppcl_id|8\n ";

my @row = split (",",$line); 
 
$date = $row[1]; 
$esid = $row[4]; 
$amount = $row[5]; 
$ppcl_id=$row[8]; 
$currency=$row[6];

my ($date, $esid, $amount, $urrency, $ppcl_id) = (split /,/, $line)[1,4,5,6,8];

my %dispatch; 
$dispatch{3} = create_func( "$pwd/BADDEBT-BACKFILL_FILE-GB"); 
$dispatch{4} = create_func( "$pwd/BADDEBT-BACKFILL_FILE-DE"); 
$dispatch{5} = create_func( "$pwd/BADDEBT-BACKFILL_FILE-FR"); 
# etc for the other files 
# now, your files are opened and the %dispatch hash contains references to functions that know where to print 
# no need to mess up with numerous file names and file handler names 
 
while (my $line=<BADDEBT>) {  
# all your code until the large if/elsif thing 
# ... 
$dispatch{$ppcl_id}->("$custid|$date|391|$esid|-$amount|$currency|$ppcl_id|8"); 
# (that's it!) 
 
sub create_func { 
     my $file = shift; 
     open my $FH, ">", $file or die "cound not open $file $!"; 
     return sub { 
          my $to_be_printed = shift; 
          print $FH $to_be_printed, "\n"; 
     } 
}