Hi,

Inherit the model 'account.move' and replace the field move_type with changing the 'Customer Invoice' to 'Tax Invoice'.

Go through the code:

_inherit = 'account.move'

move_type = fields.Selection(

selection=[

('entry', 'Journal Entry'),

('out_invoice', 'Tax Invoice'),

('out_refund', 'Customer Credit Note'),

('in_invoice', 'Vendor Bill'),

('in_refund', 'Vendor Credit Note'),

('out_receipt', 'Sales Receipt'),

('in_receipt', 'Purchase Receipt'),

],

string='Type',

required=True,

readonly=True,

tracking=True,

change_default=True,

index=True,

default="entry")

Hope it helps