I live and work in the UK as an expat. I don't have a W-2. How can I report my income in TurboTax? And how can I convert the income from GBP to USD currency?

[Andreas3000]

I already paid my UK taxes ...

[LinaJ2018 · Accepted solution]

If you are a US citizen or resident who earned wages overseas, enter your wages as foreign income.   

Use https://www.oanda.com/currency/converter/  to convert your income from GBP to US dollars.

To enter foreign earned income / exclusion in TurboTax online program:

• After sign into your account, select Pick up where you left off
• At the right upper corner, in the search box, type in foreign income and Enter 
• Select Jump to foreign income 
• Next screen, Did You Make Any Money Outside the United States? answer Yes 
• On-screen, What Form(s) Was Foreign Income Reported On ? check the third box and continue to proceed

After the exclusion, if there is a remaining amount where you need to pay taxes to both US and UK governments, you may be able to claim a foreign tax credit on that amount.  See https://ttlc.intuit.com/replies/4203946