Westpac is slamming the lid on its customers' ability to earn unlimited frequent flyer points with the bank's current family of Altitude and Earth credit cards.

A new points-capping rule is being introduced across the board, from the cheapest entry-level cards to the top-tier Platinum Plus plastic across the MasterCard, Visa and American Express editions.

As of 17 June 2013, Westpac will no longer permit an unlimited number of Qantas Frequent Flyer points to be earned each month through its line of Earth-branded rewards cards.

The basic Earth card will be limited to 2,500 Qantas Frequent Flyer points per month, while Earth Platinum and Earth Platinum Plus will be capped at 3,750 points per month.

However, bonus points earned “on selected Qantas products and services”, at the rate of one point per dollar spent, will not count towards the cap.

A similar ceiling is being imposed on the Altitude credit cards which currently funnel an unlimited number of  Westpac’s own Altitude rewards points into the frequent flyer schemes of five other airlines: Virgin Australia’s Velocity, Malaysia Airline's Enrich, Air New Zealand Airpoints, Singapore Airlines’ KrisFlyer and Cathay Pacific’s AsiaMiles.

The standard Altitude card will be limited to 5,000 Altitude points pr month, starting 17 June 2013, while Altitude Platinum and Altitude Platinum Plus will top out at 7,500 points.

As with the Earth cards, bonus Altitude points will be excluded from the monthly cap.

Westpac’s Singapore Airlines Gold and Platinum cards will remain uncapped, however, allowing SQ travellers to rack up as many KrisFlyer miles as their budget can afford.

Black is the new uber-Platinum

But all is not lost for Westpac’s point-hungry travellers: next week the bank will launch new Earth Black and Altitude Black cards.

Available from 25 March 2013, the Black cards will feature the uncapped frequent flyer points previously available through each the card’s non-Black counterparts.

In letters sent to existing Earth Platinum Plus cardholders, Westpac has advised that the Earth Black card will cost no more than their current cards.

The Earth Black American Express card will earn 1.5 Qantas Frequent Flyer points per dollar, while the Earth Black MasterCard will earn 0.625 Qantas points per dollar in Australia and 1.5 points per dollar overseas.

Follow Australian Business Traveller on Twitter: we're @AusBT