If dealing with ad hoc builds and not using TestFlight then this little Bash script has provided useful on a number of occasions. Save and run on command line passing in the path to the IPA. In return you will get the list of UDIDs in the provisioning profile it was built against,

udid_check.sh

#!/bin/bash
#
#
#

function usage
{
    echo "Usage: $0 FILE"
}

function cleanup
{
    if test -n "$tmp" ; then
        rm -rf $tmp
    fi
    exit 1
}

ipa=$1

if test -z "$ipa" ; then
    usage
    cleanup
fi

if ! test -f $ipa ; then
    echo "IPA $ipa does not exist"
    cleanup
fi

tmp=/tmp/udid.$$
mkdir -p $tmp

if ! unzip -d $tmp $ipa > /dev/null 2>&1 ; then
    echo "IPA $ipa is corrupt"
    cleanup
fi

cd $tmp/Payload/*

if ! test -f embedded.mobileprovision ; then
    echo "The embedded.mobileprovision file could not be found in the IPA. Is this a valid adhoc IPA?"
    cleanup
fi

echo "The IPA $ipa will run on iOS devices with the following UDIDs:"
echo
grep --binary-files=text -o '<string>[0-9a-z]\{40\}</string>' embedded.mobileprovision | cut -b 9-48
echo
echo "Total number of UDIDs:"
grep --binary-files=text -o '<string>[0-9a-z]\{40\}</string>' embedded.mobileprovision | wc -l

cleanup