Quote from direct.gov
Who is responsible for paying the bill?
There's one Council Tax bill for each home. Usually the person living in the property has to pay the bill. Spouses and partners who live together are both responsible for paying the bill.
The person at the top or nearest to the top of the following list has to pay the bill:
• lives in the property and owns it
• lives in the property and has a lease (this includes 'assured tenants' under the Housing Act 198

• lives in the property and is a 'statutory' or 'secure' tenant
• lives in the property and isn't a tenant but has permission to live there
• lives in the property (for example a squatter)
• has a lease of six months or more on the property, but doesn't live there
• owns the property but doesn't live there
You can't be responsible for paying the bill if you're under age 18.
If you're still unsure about who is responsible for paying the bill, you can contact your local council and they'll be able to help.
Can you proove that others lived in the house at the same time? Will the landlord give copies of tenancy agreements?