US-facing operators have been hit by an overnight crackdown on online gambling payments by credit card giant Mastercard.
The US company is believed to have toughened its stance on the widespread practice of operators coding egaming transaction as other kinds of online commerce, which will all its US customers from using their cards to gamble online.
Rival US card giant Visa is rumoured to have taken a similar measure, although this could not be confirmed at the time of writing.
The action is a sign that banks and payment companies are preparing for implementation of America’s Unlawful Internet Gambling Enforcement Act (UIGEA), which bans the facilitation of online gambling by payment companies.
This was originally supposed to have been enforced from 1 December 2009, although the US treasury later approved a delay allowing companies until 1 June 2009 to comply.
The development will increase reliance on alternatives to credit card deposits such as those offered by EwalletXpress or Poker Echecks, which work similarly to traditional paper cheques but are issued electronically, allowing players to deposit and play from an electronic wallet.
Sites likely to have been hit by the Mastercard move include US sports betting giant Sportsbook.com, which today announced that it will leave the Cake Poker network to join Ireland's Merge Gaming network.
The action by Mastercard coincides with a federal appeals court ruling this week upholding a contempt order for refusing to comply with a grand-jury subpoena against two companies owned by Canadian Douglas Rennick, who is accused of processing more than $350m in payments for Internet gambling companies.