Wellington Phoenix have been sent a bill for $1 million by Football Federation Australia for failing to hit their required off-field metrics this season.

Despite improving their home attendances by nearly 50 per cent and a significant upturn in their TV ratings on Sky Sport in New Zealand, the Phoenix still fell some way short of satisfying the contractual demands of their temporary A-League licence, which runs out at the end of next season, and must now pay $942,889.20.

The Herald understands that, as part of the four-year extension the Phoenix signed in February 2016 to remain in the A-League, the club agreed that it would meet certain benchmarks related to broadcast revenue each season. The contract provision was accepted by the club and FFA in recognition of the low value of the New Zealand market to the A-League.

Time to pay: FFA chief executive David Gallop says there are "performance hurdles" in Wellington's temporary A-League licence which must be cleared. Credit:AAP

If the Phoenix failed to hit the specified revenue number, there is a prescribed financial penalty that must be paid to FFA as a "make good". It is understood the size of the penalty increases for each year of the agreement.