Yes you can. If your own company is located in Spain or Italy, this option will appear automatically when creating an invoice.

1. Go to ‘Invoices’

2. Create a new invoice

3. The option for IRPF/withholding taxes will appear

4. The percentages are the correct ones issued by either Spain or Italy 

5. Select the right tax rate

6. Fill in the other details of your invoice

7. Teamleader will calculate the tax automatically

8. Save (and book) your invoice

The PDF of the invoice will also contain the mention of the tax.