The National Lottery Commission has confirmed that retailers will get a longer transition before the next operator licence takes effect.
Any operator, including current incumbent Camelot, would have to update terminals to ensure compliance with NLC requirements. But retailers fear havoc from any transition.
Robert Foster, NLC project board chairman, said any changeover should take 18 months instead of a year.
The deadline for bids is December 1.
Separately, Camelot has launched a new television campaign called The Big Win to illustrate the extreme happiness of winning.