How do I make rental prices include tax?

At many rental offices the price the employee quotes is the final amount, tax included. This setting makes the system work the same way: the customer pays the price you enter as it is, and the tax is taken out of it instead of being added on top.

Steps

Open Vehicle Rental → Office settings, then the General tab.
In the Prices and tax group, turn on Rental prices include tax — Figure 1.
Press Update.
From now on, every new contract page shows Included in prices under the tax column — Figure 2.

What changes

The daily or hourly rent, extra days on a late return, extensions, extra kilometres and add-ons are all entered at the amount the customer pays, with the tax inside it.
A discount and the Target Amount are taken off the tax-inclusive amount itself.
Violations stay untaxed, and so does any add-on whose tax rate is 0%.
The booking pages of your website show visitors the same tax-inclusive amount, with the tax it contains.
The journal entry and the VAT return take the correct revenue and tax out of the amount automatically.

Example

Daily price 7, tax 5%:

Without the setting: a one-day contract totals 7.350 — 7 plus 0.350 tax.
With the setting: the total is 7.000, of which 6.667 is revenue and 0.333 is tax. The customer pays 7 and the contract closes with nothing outstanding.
If the car comes back after three days, the total is exactly 21.000, not 22.050.

Notes

The setting applies to new contracts only. Each contract keeps its method from the moment it is created, so turning the setting on or off never changes an existing contract.
Before turning it on, review the saved vehicle prices: they will be treated as tax-inclusive. If they were entered before tax, update them first.
The Target Amount field stays for agreeing a lower amount than usual with a customer; the difference is recorded as a discount.
If the setting is changed while an employee has the new-contract screen open, the system refuses the save and asks them to review the amounts, so a contract is never saved differently from what the employee saw.