OK - So I am no way a tax expert so be sure to validate this information with your tax professional. I do have experience as a business manager as well as a degree that included 300 and 400 level accounting and finance course work).
For the last 20+ years, I am always asked about deducting point of sale system expenses from your taxes as an expense. For most retailers, the answer is yes - an outright purchase of point of sale hardware and software can qualify as a deduction. The requirements are that the hardware is being used in the business and not for personal use.
Some gray areas include if you can deduct point of sale hardware that you are leasing as well as point of sale software that you pay a monthly subscription on.
At any rate, if you have not used up your computer hardware deductions for 2020, now is a great time to look at investing in a new POS system. At this point, you should expect that you will pay for the point of sale system now but not have the new system installed until 2021.
One last thought - don't wait until the last week in December to try and purchase a new point of sale system for tax purposes - I've had lots of folks call me on December 31st and generally it's too late with most staff (and most companies) closing early on New Years Eve. A good deadline (depending on what you need) is having everything finalized by Dec 15th, 2020. This allows time to process payments and get you that much needed invoice/receipt showing that the POS system was paid for in 2020.
Thoughts, comments and suggestions on the above are welcomed! You can reach me at firstname.lastname@example.org or 208-340-5632.