Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: “Encoding checks itself can be considered as a neutral service and like all other services it is considered as halal. Originally all things are considered halal unless proven otherwise.
Checks belong to the category of essential services in today’s society because much of our economic life depends upon them in an industrialized society, and as such there is nothing intrinsically wrong with it; it can either be used beneficially or otherwise.
If no one contributed to make this service available, a great deal of economic activity would come to a halt. Hence, there is no legitimate ground to prevent a Muslim from being associated with this service. Although this is associated with banks, it still can be treated in itself, as a halal service.
In light of the above, I do not think one’s earnings fall under the category of haram —provided that your intention is to obey Allah. However, I must add a further word of caution: if it bothers your conscience, then you are better advised to leave it.”