Town are expecting a crowd of around 20,000 for Saturday’s match against Hull City with the club running a ticket promotion.
Ticket office manager John Ford told the club site: "It’s obviously a big game for both clubs and we should have a good crowd.
"We’re over the 18,500 mark already and Hull will be bringing around 700 fans. I’d expect us to be close to the 20,000 mark.”
Season ticket holders are able to buy up to four additional tickets at £10 each for adults, £8 for concessions and £3 for juniors.
Silver members are entitled to buy their ticket at £20 for an adult or £10 for a senior citizen, and can also purchase up to four additional tickets at £10, £8 or £3. Full details are on the club site here.
The Blues’ last home game, the 3-0 victory over Leeds, was watched by 20,402 supporters.