This is completely up to you and the landlord/seller. The municality will look to whomever is the owner of the property at the time (presumably the seller, until the full, agreed-upon price is paid), but you and he/she can agree among yourselves to have you pay some or all of the taxes. Such an agreement to shift the tax burden to you is enforceable, and if there were such an agreement and you failed to pay the taxes, while, as stated above, the municipality will look to the seller for the taxes, he/she could in turn sue you for the amount you agreed to pay.