Did you mean income taxes ? If not why do you think you owe any sales taxes ?
The excavation contractor is charging me sales tax.
Every state has its own list of what is subject to sales tax.
This forum is primarily an "income tax" forum and sales taxes involve an entirely different set of rules.
I would think that, broadly speaking, "services" aren't subject to sales taxes, but even services can have elements of tangible "stuff" that goes along with the service, and subject to sales tax.
Generally sales taxes are charged to the "consumer", not an intermediary, e.g., wholesaler, retailer. If you are properly charged sales taxes then, generally, that gets added to your basis, i.e., the rental property. But if you are legitimately being charged sales taxes you can't "wait" to pay them. You pay them when you make the purchase.
Check with your state as to exactly what is subject to sales tax.
A sales tax is imposed by a state or lower government (such as city). It is paid at the time of the transaction. If you are going to claim a sales tax deduction for a large purchase, then you must claim/deduct it in the tax year it was paid. You can't carry it forward. Also be aware that the sales tax deduction is a oart if the SALT (State And Local Taxes) limits that started in 2018.