# stdnum.fi.alv

ALV nro (Arvonlisäveronumero, Finnish VAT number).

The number is an 8-digit code with a weighted checksum.

    >>> validate('FI 20774740')
    '20774740'
    >>> validate('FI 20774741')  # invalid check digit
    Traceback (most recent call last):
        ...
    InvalidChecksum: ...

stdnum.fi.alv.checksum(number: str) → int

  Calculate the checksum.

stdnum.fi.alv.compact(number: str) → str

  Convert the number to the minimal representation. This strips the number of any valid separators and removes surrounding whitespace.

stdnum.fi.alv.is_valid(number: str) → bool

  Check if the number is a valid VAT number.

stdnum.fi.alv.validate(number: str) → str

  Check if the number is a valid VAT number. This checks the length, formatting and check digit.