Additional seats can be bought at a discounted price of two for £20 up to a maximum of ten tickets.
Tickets are on sale to now to season card holders with prefix A for Boro's trip to Arsenal on April 26 (1.30pm). Boro have been allocated 1,410 tickets, priced £32.50 adults and £16.25 for over-65s and U-16s.
Remaining season card holders will be able to purchase them from April 2.