Yes its allowed and only storing this (not full PAN) it puts you out of PCI-DSS scope.
https://security.stackexchange.com/questions/168601/does-transmitting-first-6-and-last-4-digits-of-the-card-number-and-expire-date-r?newreg=2880a7713c37401bb1434c6133e106aa
https://www.pcisecuritystandards.org/faq/articles/Frequently_Asked_Question/Are-truncated-Primary-Account-Numbers-PAN-required-to-be-protected-in-accordance-with-PCI-DSS/