German and US passports - which to use when?

A friend at work has dual citizenship, German and US. She works in the UK using her EU status.

She asked me a question today about travelling to the US and I wasn't certain of the answer so I told her I'd ask on the board.

When she leaves the UK to enter the US should she present her US passport at Heathrow and use it to enter and leave the US? When she arrives back at Heathrow should she use her German passport for re-entry?

Thanks.

American citizens are required to enter and leave the United States using their US passports- it's illegal to do otherwise.  Once landing in the UK though, she'll need to show her German passport as evidence of her right to live here.

So when she comes back into the UK does she go through the EU citizen line or through the line for non-citizens?

She told me the last time she came back in on her German passport immigration officials tried to take it away from her and held her in immigration control for over two hours because she had two passports on her.

However she is very aware that she has to show her German passport on re-entry because that's what gives her the right to live and work here. She just doesn't want to go through the same stress as last time.

Are there any rules that she could print out to give to immigration at Heathrow if they give her a difficult time again?

So when she comes back into the UK does she go through the EU citizen line or through the line for non-citizens?

The EU line.

Plenty of people who are dual citizens do the two passports thing going to and from the US...she shouldn't have to show both passports at the same time, but even if she does the hassle she experienced the last time is likely not the norm.

upon re-entry into the UK she should only show her German passport, there is no need to show her American one.  Sounds like the IO was just being a pratt.

She told me the last time she came back in on her German passport immigration officials tried to take it away from her and held her in immigration control for over two hours because she had two passports on her.

No offence, but I find that very difficult to believe.  Perhaps they wanted to check it, but there is no reason for anyone to have a problem with this.

Vicky