USAGE 

There are multiple levels of rounding precision you can set on your SOs, invoices, taxes. One of them is the Cash Rounding Method.

This is used to round your tax amounts. This might be very needed when your cash machine does not show the same amount of tax than your invoice in Odoo.

HOW IT IS WORKING IN ODOO

1. Enable 'Cash rounding' in the accounting settings

2. You now have a new menu in the accounting configuration called Cash Roundings

3. Go in this menu and create a new rounding

4. You can now select your cash rounding method on a draft invoice

Rounding Precision: if set 1, the amount will be rounded to the unit

Rounding Strategy:

> Modify tax amount will adjust the tax amount

> Add a rounding line will add an invoice line with the associated account with the objective to round the total (amount_total) with the rounding precision

Rounding Method: 

> UP will round up.

> DOWN will round down

> HALF UP will round to the closest. For example: with an precision of 0.1 ; if calculated tax is 2.31 it will round to 2.3. If calculated tax is 2.37 it will round to 2.4.

/!/ The rounding is computed based on the decimal places set on the currency! As a result, a 0.01 rounding precision on a currency with 2 decimal places will be useless as the currency already rounds the amount with a 0.01 precision.

For example

With a rounding precision of 0.1, modify tax amount strategy and rounding method UP
Create an invoice and choose the rounding method you just configured.
Add a product with 
- qty 1
- Unit Price 10.5
- Tax 21% (non included)
Tax should be: 10.5*0.21 = 2.205
With the rounding method, it rounds the tax amount UP to 2.3