No, it's not and it will never be right.
If you're a believer, will you do the same? Sadly, even some Christians practice it, without being bothered by their conscience.
Using other people's official receipts to compute another income earner's tax deductibles is a brazen way to cheat on taxes. People take this very lightly, but such dishonesty is a form of stealing from one's inland revenue.
The COA commissioner once said that it's not easy to teach people integrity. That's true. But at least, let's listen to this: Stop cheating, be honest, and be brave to do what's right in the eyes of God and man.
If you've decided to use other people's official receipts to compute your tax deductibles, take heed. The inland revenue bureau may not catch you, but God sees what you do. Fear Him (Luke 12:5).
Thou shalt not steal. (Exodus 20:15)