The 30th September is a deadline for filing income tax payment returns (IRPF) for 2015, according to the Government of Andorra.
From 15th September the tax authorities’ timetables will change to give the taxpayers of Andorra (Pyrenees) an additional opportunity to comply with their tax obligations. In particular, the declaration can be submitted on days including Saturday 17th and 24th September. Opening hours are from 8:00 to 15:00. Pre-registration is required.
On 30th September, the last day of the declarations, the tax authorities will work until 18:00.
In accordance with the tax legislation, sanctions will be applied to cases of noncompliance with this obligation.
Look here for details about tax system of Andorra
See also Andorra business guide
See also Andorra company formation