Retroactively set aside tax?

[Katie472]

I have property in the Catskills, ulster county and was recently informed I need to charge 2% occupancy tax. I don’t understand how I am meant to do this and record it retroactively. Can I just take 2% from all previous bookings and wet it aside for tax? Why is there no way to incorporate it in the nightly cost? Doing the resolution center route or asking people to pay in cash is not a viable option.