Can I file my taxes now and pay for your services later

First of all you cannot file a tax return online "now" at all.  E-filing is not open, and will not be open until sometime in January for 2020 returns.  

If you want to pay an extra refund processing fee of $40 ($45 in CA) to have your fees deducted from your federal refund by a third party bank when you are ready to file, then in the FILE section you can choose that option IF your refund is enough to cover your fees + that extra $40.

Please be careful about being in too much of a hurry to file your next tax return. Many tax forms are not available at the very beginning of the tax season, so you have to wait for your forms. The software still needs updates at the beginning of the tax season. 

Although the software will allow you to e-file in early January, the IRS does not begin to accept the e-files until almost the end of the month.  So your return just sits on the server.  If you realize that you made a mistake or left something out—as many people do—you cannot change it.

Every year we see people who are in such a rush to file that they file incorrectly and incompletely.  If you file too early and leave out a W-2 or a 1099, or forget to enter information, you will end up having to amend your tax return---and that takes months.  Employers have until the end of January to issue W-2's----and ALL of your 2020 W-2's have to be on the same tax return.  Many of the 1099's and 1098's you need do not arrive until late January or sometime in February.  If you are getting Earned Income Credit or Additional Child Tax Credit, the IRS is going to hold your refund until the end of February no matter how early you file.  There seems to be a greater chance of "early" returns being reviewed and those refunds are delayed, or early returns are more often subject to identity verification--which will also delay processing.  Filing too early may just be a recipe for a delayed refund.  It might go more smoothly for you if you wait until at least mid-February to file instead of e-filing during the first minute that you can do it.