When you compare service contracts, you probably look first at the total and then at the plan terms. Before you decide the total means anything, look for the lines that come from outside the plan. Some are set by the state where the contract is sold or where the car is registered. Others come from the paperwork the seller uses to file the contract.
Start with the tax question
Whether sales tax applies to a service contract is not the same everywhere. In some places it applies to the contract price, in others it does not, and some places treat the tax differently depending on whether the contract is sold with the vehicle or later. Do not assume either answer. Ask the seller which rule applies and where the tax line comes from. If the answer is that the tax is simply part of the total, ask for it to be written on its own line so you can see it apart from the plan price.
Filing and administration lines
Some contracts carry a line for filing or registration. That charge may pay for paperwork the company must file with a state regulator, or it may be a seller charge labeled to look like a government fee. The difference matters. A true government fee is generally the same no matter who sells the contract. A seller charge can change from one dealer to the next. Ask what the line is, who receives the money, and whether it appears on every version of the contract the seller offers you.
Compare the total the same way
To compare two quotes fairly, put the tax, the filing line, and the plan price side by side. A quote that looks lower may carry a higher tax line, or may leave a filing charge off until the signing table. Ask each seller to write every charge on one page. If a seller will not do that, treat the quote as incomplete and do not compare it against a complete one.
This site does not publish tax or filing figures for each company, because those depend on where you live and who sells you the contract. For the published company terms, start with the comparison table on the ranking page, then read the methodology page to see how we add up what each company prints. The table shows what a company publishes, not what your seller will charge you, so the final total is still yours to check on the paperwork in front of you.