I am not sure which form of "Thank you" I should use. Is teşekkürler more casual while

teşekkür ederim is formal? Does it matter which one I use?

Thanks for your help in advance.

Is teşekkürler more casual while teşekkür ederim is formal?

Your diagnosis is correct.

Though the two can be interchangeably used, I would always use "teşekkür ederim" to be on the safe and correct side.

Good question, I was going to ask this as well. Someone told me that "teşekkürler" is the plural form used to more than one people?

I get really confused.

I think teşekkürler is the direct translation of thanks and broken form of teşekkür ederim.

You should use teşekkür ederim.

Teşekkür ederim!

Thank you Umut. I will use teşekkür ederim then.