Do I have an obligation to answer honestly when a credit card company asks me to enter my income?

Similar: https://www.fluther.com/236246/should-i-give-my-credit-card-companies-my-updated-income-information/

I don’t tell them or make something up.

I haven’t answered in 20 years. I just leave it blank.

I don’t need a higher credit limit.

Nope. Enter any number you like to get what you need from them. They just want your interest payments.

Usually you can skip. I think it is fine to lie if it is an amount that is less than the truth.

Zero obligation. It’s a marketing tool, and a way to see if they think you can qualify for a higher credit limit. Skip it.

I don’t lie intentionally, but I don’t know off the top of my head without bothering to look for it. So I usually just estimate what it is and no doubt I’m not exactly accurate.