Pompey fans will have to enter a ballot to get tickets for the FA Cup match at Maidenhead.
The Blues have been given 660 tickets for the first round tie at York Road on Saturday, November 10 (12.30pm kick-off).
Most are terrace places, with just 175 seats available for away supporters.
Only season ticket holders and former shareholders will be able to enter the ballot (one ticket per season ticket holder/shareholder), which is now open and will close at 5.30pm on Thursday, November 1.
Applications can be made on the official Pompey website, by calling 0345 646 1898 or in person at the Anson Road ticket office.
Kenny Jackett’s Blues are determined to enjoy a good FA Cup run this season and will be ready for a difficult trip to their National League hosts.
Fans will be able to select their preference for seating tickets or standing.
Supporters can also apply in a group if their accounts are linked. Depending on the result of the ballot, either everyone in the group will be allocated a ticket or nobody will.
Applicants will be informed by email whether or not they have been successful. Fans who do not receive a ticket will be able to watch the match live on BT Sport 1.
Seats are £20 for adults, £15 for concessions and £10 for juniors.
A terrace ticket is £15 for adults, £10 for concessions and £5 for juniors.