Taxes and Fines

Q: I have just engaged in seaport clearing agency insha Allah with the aim of observing Shariah and sunnah. But I'm faced with the following questions.

1. Short payment to the government custom duty is common. Is it allowed? Short payment is paying for HONDA 1999 instead of 2003. Majority are involved in this  even the custom officers overlook this.  Contracting the clearing out makes the case worse as they will hide the short payment.

2. Also in the clearing offices people pay some amount that are already normal things over there but are without receipt. Are we allowed to
pay such money when we don't have options and its already their system. eg vehicle examnation officer will not leave his office unless such amount is paid. No special treatment will be given for ones job except that its their norm.

3. Police on the way also ask for money even after you have correct papers. Can we give them money?

Q: I work for a company that imports fabric. In order to avoid paying the full customs amount, we change the amount of goods declared. For example, if there is a roll of fabric that is 150m in length, we tear the label off and write 50 yards by hand. Is this allowed?

Q: 

1. Is paying Income tax Halal or Haraam?
2. Is it permissable to get offer from merchants? for eg : 10% discount, Buy 1 get 1 free etc?

Q: Our government has imposed 30% duty on import of machinery on trade license but if we import on manufacturer license then the duty is 10%. But the manufacturer is not allowed to resell the machine. I was importing machines on someones manufacturers license and sell to my customers and save the tax. Now I am very much confused that either it is halaal or haram? Similarly my machine price is USD 14000 c&f but the government has fixed the amount USD 9700. So we under invoice to USD 9700. Please also let me know that either it is allowed or not?

Q: Is it permissible to evade paying money to the tax authorities by not disclosing all transactions, etc.?

Q: I will be going for my driving licence soon and I wanted to know mufti saab since the halaath of our ummuth is so bad and its full of corruption and that makes getting my driving licence even much harder to get and also an increased chance of failing, my question is about paying an extra fee which will go to the inspector for passing me. What should I do?

Q: 

1. Muslim School fines parents £100.00 if they take children for a holiday during school term; the parents are forced to pay the fine, is this permissible? 
2. If it’s not permissible for Muslim School to fine the parents £100.00 for taking children for a holiday during school term, and the School have fined the parents on previous occasions what should be done with the money, is it permissible for the School to use the money?