From the FA Cup rules...
23. PROCEEDS OF MATCHES PRIOR TO THE SEMI-FINALS
(a) The net gate receipts due from a match (except replayed matches in consequence of a breach of the Rules) shall be the total ticket sales for the match less VAT, the travelling expenses of the Visiting Club, the fees and expenses of the Match Officials, and other match expenses allowed under the Competition Rules (which include costs relating to gate attendants, turnstile operators, stewards, weather reports, police charges, floodlighting in accordance with the Competition Rules, contributions to the costs of First Aid Helpers and any costs relating to clearing the ground of snow and water provided the Visiting Club is consulted beforehand on the approximate costs). Any shortfalls in receipts are the responsibility of the home club and are not to be shared. The Council shall have the power from time to time to issue instructions as to what shall and shall not be allowed as a match expense.
( Net gate receipts shall be divided as follows:
(i) In matches prior to the Third Round of the Competition Proper (other than replayed matches in the Competition Proper), the net gate receipts of each match shall be divided equally between the competing Clubs.
(ii) In replayed matches in the Competition Proper prior to the Third Round, 5% of the net gate receipts shall be remitted to The Association and the balance shall be divided equally between the competing Clubs.
(iii) In matches played in the Third, Fourth, Fifth and Sixth Rounds of the Competition Proper, the net gate receipts of each match shall be divided as follows:
45% to each Club competing in the match.
10% to the Pool.
(iv) In replayed matches in the Third, Fourth, Fifth and Sixth Rounds of the Competition Proper the net gate receipts of each match shall be divided as follows:
5% to The Association.
42½% to each Club.
10% to the Pool.
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(d) In matches played in the Third, Fourth, Fifth and Sixth Rounds of the Competition Proper involving Clubs outside the FA Premier League or The Football League, the net gate receipts of each match shall be divided as follows:
50% to Clubs outside The FA Premier League or The Football League.
40% to FA Premier League or Football League Clubs.
10% to the Pool (save where both Clubs are outside The FA Premier League or Football League).
(e) In replayed matches in the Third, Fourth, Fifth and Sixth Rounds of the Competition Proper involving Clubs outside the FA Premier League or The Football League, the net gate receipts of each match shall be divided as follows:
47½% to Clubs outside The FA Premier League or The Football League.
37½% to FA Premier League or Football League Clubs
10% to the Pool (save where both Clubs are outside The FA Premier League or The Football League).
5% to The Association.
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The full rules are here