Here is a copy of a recent post which I contributed to Facebook which answers a lots of your questions. You probably need only the first few forms mentioned (1040, Schedule B, 2555, 8965). I recommend you prepare the 2015 return first. That will teach you how to do it, and then you can subsequently prepare the 2012-14 for streamlined. You will send the package of 3 streamlined returns to Austin TX, separately from the return for 2015. You get an automatic extension to June 15. Read here for information about how to extend this to October 15.
https://www.irs.gov/Individuals/International-Taxpayers/U.S.-Citizens-and-Resident-Aliens-AbroadHere begins the quote from Facebook:
You can do it yourself. That is quite feasible. I know at least one tax professional who says that he always recommends that potential clients see if they can do it themselves first. --- If so, great. Here is a bit more information about what you need to do if you want to become compliant and continue as a US citizen.
1. You can read about the streamlined offshore procedures here
https://www.irs.gov/.../U-S-Taxpayers-Residing-Outside...
You will need to file 3 years of IRS income tax returns, say 2012, 2013, 2014, and Form 14653. You will send these in a single envelope to Austin TX. You will also file six years of past FBARs, 2009-14, which you can do online. The 2015 needs to be done by June 30, so this is your first important deadline.
2. You separately file 2015 FBAR and 2015 1040 return (not via streamlined) and continue to file these returns each year for the rest of your life, or until the year after you renounce. [**You will need to be careful about your financial planning going forward so that you do not mistakenly invest in things that are sensible from a German point of view, but could someday incur nasty US tax. If, for example, you were to win the top prize in Euromillions that would be US taxable.**]
3. To prepare your IRS income tax returns you will need various forms. Which forms you need will depend on your circumstances. If your circumstances are really simple you might not need any software program and can just download the forms you need from the internet and read the instructions that come with them. Google, for example, "1040 instructions 2013". In more complicated circumstances I recommend buying the download version of TaxAct Plus ($29.99), which has all the forms, calculates the tax, and makes printing them easy. They also sell the programs for past years. Here is a list of forms you might need. If your circumstances are simple you may need only a the first few. Maybe others can suggest other things and advice. But I am trying to keep this simple
1040 (this is the top page of your tax return and your main return)
Schedule B (bank interest and dividends);
8965 (health care exemption, exemption type C);
2555 (exclusion of foreign earned income up to $100,800), and/or
1116 "passive", "general" & "resourced by treaty" versions (to claim foreign tax credits for German tax you have paid);
8938 (report of foreign accounts, if you have >$200,000 in such);
8833 (to claim a treaty position on a foreign pension plan);
Schedule A (itemized deductions, such as mortgage interest, though it may be simplest just to ignore this and take the standard $6,300 deduction);
Schedule C (own business);
Schedule D (capital gains);
Schedule E (other income, such as rental property income, book/music royalties).
8621 (foreign mutual funds subject to 1291 fund PFIC tax);
Ask here and on the Facebook page "US Expat Tax Questions". There are lots of people who are willing to help.
It would be useful to compile a list of FAQs and other points. Here are some with which to start.
(a) Take the IRS quiz. Do I Need to File a Tax Return.
https://www.irs.gov/uac/Do-I-Need-to-File-a-Tax-Return%3F(b) Read the IRS advice here:
https://www.irs.gov/.../Internati.../Taxpayers-Living-Abroad(c) You don't have any W2 forms with which to report your wages. Work from your own payslip records. Convert your foreign country wages to dollars using the exchange rates here:
https://www.irs.gov/.../Yearly-Average-Currency-Exchange...
(d) The above can be considered US EXPAT TAX 101. For those who are up to the challenge of US EXPAT TAX 201, there some other forms to understand. But if you need these then you probably need professional help.
5471 (you own 10% of more of a company regarded as a Controlled Foreign Corporation)
3520 (you are involved with foreign trusts)
(e) Phantom currency gains. Suppose you take out a £100,000 mortgage when the $/£ rate is 1.50. The IRS see you as having borrowed $150,000. Some year later you pay back £10,000, but the $/£ exchange rate is now 1.40. The IRS see this as costing you only a $14,000 repayment, so you have profited by $1,000, which is now US taxable. On a repayment mortgage this sort of thing can happen with each monthly mortgage payment. Never mind that no real dollars have ever been involved.