Praise be to Allah.
What appears to be the case from your questions is that you are suffering from waswasah (whispers from the Shaytaan). Our advice to you is to ignore the matter and pay no attention to it, and do not ask about it. This is the best remedy for it.
We do not know whether you are asking about something real or something hypothetical. If it is hypothetical, then we say that the Muslim’s attitude should be to refrain from going out of his way to ask about something that has not happened, and this is more appropriate in the case of one who is suffering from waswasah, because by asking such questions he is opening the door to evil for himself, and other types of waswasah.
There is nothing wrong with using money on which there are images of animate beings, because the problem is so widespread and there is a real need to use it.
Some of the fuqaha’ are of the view that it is permissible on the grounds that these images are handled with disrespect.
Others are of the view that it is permissible on the grounds of necessity.
In Fataawa ar-Ramli (3/196) it says:
He was asked about coins on which there is the complete image of an animal – is it haraam to carry them, like the prohibition on wearing garments on which there are images, and is it permissible to use them for istinja’ (cleaning oneself after relieving oneself), on the basis that it is haraam to carry them, or not?
He replied: It is not haraam to carry them, and it is not permissible to use them for istinja’ (cleaning oneself). Ibn al-‘Iraqi said: In my view, Roman coins on which there are images come under the heading of that which it is not forbidden to carry or use, because the way it is handled is with disrespect when spending them, and when giving or taking them. The early generations (may Allah be pleased with them) used to use such coins with no objections. Islamic coinage was not introduced until the time of ‘Abdul Malik ibn Marwaan, as is well known. End quote.
The Standing Committee for Issuing Fatwas was asked: I am very worried about some things, one of which is the issue of images on money. We are faced with this problem, and it is brought into the mosque in our pockets. Is bringing it into the mosque something that causes the angels to leave, and is it haraam to bring it in? Is it regarded as being among the things that are handled with disrespect, in which case images that are handled with disrespect do not prevent the angels from entering houses?
Images on money are not your fault, and you have no choice but to possess it and keep it in your house, or carry with you in order to use it for buying and selling, giving as gifts or in charity, and paying off debts, and other legitimate purposes. So there is no blame on you.
It does not come under the heading of that which is handled with disrespect; rather it is something that is regarded as valuable, because of the value of what it represents of cash. Rather you are not to blame, because it is a matter of necessity.
End quote from Fataawa al-Lajnah ad-Daa’imah, 1/704
Shaykh ‘Abdullah ibn Qa‘ood, Shaykh ‘Abdullah ibn Ghadyaan, Shaykh ‘Abd ar-Razzaaq ‘Afeefi, Shaykh ‘Abd al-‘Azeez ibn ‘Abdullah ibn Baaz
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
As for a man carrying with him that which has become a widespread problem among Muslims nowadays of money on which there are images of kings and presidents, this is an old issue that has been discussed by the scholars. People here (in Saudi) used to carry foreign money on which there was a picture of a horse and knight, and they used to carry French currency on which there was the image of the head and neck of a bird.
What we think is that there is no sin on the one who carries money with him, because there is a need for him to carry it, because people have no choice but to keep the money in their pockets, and disallowing that would cause a great deal of hardship to people. Allah, may He be exalted, says (interpretation of the meaning):
“Allah intends for you ease, and He does not want to make things difficult for you”
“and has not laid upon you in religion any hardship”
It is narrated in a saheeh report from the Prophet (blessings and peace of Allah be upon him) that he said: “Religion is easy and whoever overburdens himself in his religion will not be able to continue in that way. So you should not be extremists, but try to be near to perfection and receive the glad tidings that you will be rewarded.” Narrated by al-Bukhaari. And he said to Mu‘aadh ibn Jabal and Abu Moosa, when he sent them to Yemen: “Be easy going and do not be harsh, give glad tidings and do not put people off.” And he said to the people when they rebuked the Bedouin who urinated in the mosque: “Let him be, for you were sent to make things easy; you were not sent to make things difficult.” Both reports were narrated by al-Bukhaari.
So if a man carries money on which there are images, or an ID card, or a driver’s license, and he needs it or thinks he will need it, there is nothing wrong with that, and there is no sin on him, in sha Allah, because Allah knows that he dislikes these images and does not approve of them, and were it not for that need, he would not carry it.
End quote from Majmoo‘ Fataawa Ibn ‘Uthaymeen (2/280).
If there is any money on which there is an image of a statue or one of the gods that some of the polytheists worship, it is not haraam to carry that money or to use it, because it is not you who put that image on it and you do not approve of it, and you have no choice but to carry that money and use it. Similarly, there is no blame on you either if you sign the letters that are sent to you, even if there are stamps on the letters on which there are symbols of kufr, as you mentioned, such as if the stamp has the image of an ancient temple or the image of a statue. You did not put any of those stamps on it, and all you have to do is sign the letter.
If you are required to add a stamp, then try to avoid anything on which there are images of animate beings, or symbols of kufr, if that is possible and if there is an alternative that is acceptable to the authorities.
If there is nothing else available, then there is no blame on you, because of the widespread nature of this problem and because of the necessity, so long as you dislike the images and disavow them.
And Allah knows best.