Generally, this works best for all parties because the landlord, especially one who owns several properties, can normally get a better rate from an oil company based on volume than an individual tenant could negotiate. In this case, you get stuck paying higher rates than you should. If this happens, call a variety of oil companies and draw up list of the estimates you obtained. Speak with your landlord about what you have discovered and what can be done about switching companies. If you have oil heat, your landlord has probably already chosen an oil company.
Landlords normally can get better rates especially if they own several properties.