Sharing wifi purchase

If I purchase a 12 month wifi package, am I allowed to "share" the username and password details with family members? I can't find any T & C on here, and I'm not on a CC site whilst writing this, so I can't access the wifi payment details.

For example, I have a pitch booked for a weekend, then my parents are taking over the booking for ten days, then I return to take over the booking. Is it OK to leave my parents my username and password so they can use my wifi access in my absence?

They are also members, but only use my van maybe once a year, so there is no point in them paying the annual subscription.

We'll be at Moreton, which I believe has reasonable wifi.

Thanks in advance,

ADL