Microsoft insists it is just looking at the possibility of enforcing charges, but it seems pretty likely that it will.
According to a Microsoft press statement, any charges imposed will be on premium services only.
"The charges will not affect existing services such as Hotmail," said a Microsoft spokesperson. "It would only be for additional offerings, such as the recent Madonna Live music event."
"We don't have any figures at this stage," said the spokesperson.
But the figure seems likely to be around £60 (around $160). This was the amount that Neil Holloway, Microsoft UK manager, said in a statement today he thought people would be willing to pay.
Industry rumours say Microsoft has incurred major losses from its MSN portal. It's invested £600,000 (over $1.6 million) updating its site so keeps up with competitor sites such as AOL and Yahoo. But users may begrudge paying additional fees to the multimillion pound giant.
MSN is the UK's biggest Web site attracting, around three quarters of the UK's 20 million internet users.
The move may mark the beginning of the end of free Internet content, if other portals choose to follow suit. AOL confirmed that at this stage it had no plans to enforce any charges.