Working abroad - living in Indonesia

Hi Duende, its a grey area, formally a family Kitas holder Is not allowed to work, but there Is also a law that state that foreigner with indonesian spouse can help their spouse to esrn Money to support the family.
I can suggest to talk with the immigration office where u live, explanimg that u want pay tacx on ur job, every office has its personal interpretation of that law.
If they will allow u to do that job, u must
register at the Tax Service Office (Kantor Pelayanan Pajak) in your city of residence. Expats living in Jakarta are required to register with the Tax Office for Foreign Bodies and Expatriates (KPP BADORA).

Your registration, monthly tax payment and annual return can be prepared and submitted by appointed representative, usually an accountant specializing in tax matters. Be sure that you receive a good referral, as remember you yourself are legally accountable for any non-payment of taxes.

To register you need:

a completed registration form
photocopies of all the pages in your passport
photocopy of your work permit
certificate of domicile for you and your employer
photocopy of your employer's NPWP
Letter of Authorization, authorizing your representative to register and handle your tax matters.
While the registration form only asks for copy of ID page of passport and does not request the other items mentioned above, the bureaucrats at the Tax Office ask for them as a matter of course.
Once you have registered, taxes are due and payable beginning not later that the 15th day of the following month and reports should be submitted to the tax office by not later than the 20th day of the same month.