The second-tier showdown has being made part of an NHS app trial with an increased capacity of 12,000.
Confirmation comes as the Government clarified guidance for eight areas considered hotspots for the Indian variant of coronavirus, which includes the borough of Hounslow where Brentford are based.
There had been confusion over whether local lockdown had effectively been put in place in the west London borough, but on Wednesday it was confirmed there are no travel restrictions in or out of the borough.
The increased allocation will mean almost 85 per cent - or 10,000 - of the available tickets will go to supporters of the two Championship clubs, and 80 per cent of the 10,000 capacity for the League One and Two finals, greater proportions than in pre-Covid days.
Remaining tickets will be split between Club Wembley, event organisers and sponsors.
An EFL spokesperson said: "Having moved our play-off schedule to align with the Government's move to Step 3 protocols and enable fans to attend, we look forward to welcoming supporters back to Wembley at the eagerly anticipated Sky Bet EFL play-off Finals, after a season behind closed doors.
"While the small increase in the Championship Final is welcome, we would of course have preferred to admit fans in much greater numbers, but like other public events are subject to the Government's Step 3 guidance.
"Unfortunately, the play-offs were not selected to operate as a pilot event as part of the Government's Events Research Programme - despite a request from the EFL on behalf of the clubs involved and their supporters - which meant that achieving significantly greater capacities at all three Finals was not possible.
"The EFL shares the disappointment of the clubs and their supporters that many fans will be absent but we will continue to liaise with the Government in the coming weeks as we pursue our aspiration of a return to full stadia for the start of next season."
Additional reporting by Press Association.
