Should I keep copies of my business's invoices for tax records?
It's always beneficial to have detailed business records.  There are any number of reasons where you'd need to prove both the types of services you've rendered and the payment history - you've already noted audits (for IRS taxes).  Other possibilities: Whether these records need to be original or electronic might be the topic for another question.
"I don't see why you would need an ""international tax specialist"". You need a tax specialist to give you a consultation and training on your situation, but it doesn't seem too complicated to me. You invoice your client and get paid - you're a 1099 contractor. They should issue you a 1099 at the end of the year on everything they paid you. Once you become full-time employee - you become a W2 employee and will get a W2 at the end of the year on the amounts paid as such. From your perspective there's nothing international here, regular business. You have to pay your own taxes on the 1099 income (including SE taxes), they have to withhold taxes from your W2 income (including FICA). Since they're foreign employers, they might not do that latter part, and you'll have to deal with that on your tax return, any decent EA/CPA will be able to accommodate you with that. For the employer there's an issue of international taxation. They might have to register as a foreign business in your state, they might be liable for some payroll taxes and State taxes, etc etc. They might not be aware of all that. They might also be liable (or exempt) for Federal taxes, depending on the treaty provisions. But that's their problem. Your only concern is whether they're going to issue you a proper W2 and do all the withholdings or not when the time comes." I heard from someone that since my friends are moving money to my account, I'm liable to be taxed by the IRS  Not completely true. If there are large deposits in your account, you may be asked for clarification from IRS. If there is a reasonable justification; in your case the agreement that you are sharing the apartment, the lease deed has all the 3 names, there is explicit mention in lease about how funds are transferred. Note at times the audit maybe in future for quite a bit of past. Hence you would need to keep the record for quite some time. Alternative arrangements like opening a joint account and making payments from that account may make it easier from record keeping point of view. You're gonna start a business but you can't choose your own name? C'mon man, that's the fun part.. Have you researched the demand? In a dying industry like hard copy games, what sets you aside from big players like GameStop? What's gonna set you apart from all the rest? Sorry to say but right now you don't even have a name, my friend. My advice is to write out a detailed business plan &amp; come up with ways to keep yourself afloat. Either way, like I said, you're entering a dying industry that may have something like 10 years at the max considering digital copies are becoming the majority. Personally, i'd rethink your business concept because you may be calling it Game Over before you even push start.. Good Luck I am a freelancer based in Europe and I want to tell you: - if you are a freelancer, then you INVOICE your Swizzerland based client The word salary is improper. - So your client will DEDUCE the invoice from its taxes, and NOT pay income tax on top of that invoice. Because invoice = expense.  So, ONLY YOU pay income tax in India. Your client pays no tax at all, not in India, not in Swizzerland. As you are a freelancer and not employee, the company has no obligation to pay employer taxes for you. A company  has financial benefits from working with a freelancer. Just type in the forms as they are, separately. That would be the easiest way both to enter the data without any mistakes, and ensure that everything matches properly with the IRS reports. I'd imagine you want to keep the utility bills around to dispute any historical billing errors or anomalies for perhaps 6 months to a year. Beyond that, you always have the financial records of making the payments -- namely, your bank statements. So what benefit is there in keeping the paper receipts for utility payments around for longer than that? I say shred them, with extreme prejudice -- while wearing black Chuck Norris style. "-Alain Wertheimer I'm a hobbyist... Most (probably all) of those older items were sold both prior to my establishing the LLC This is a hobby of yours, this is not your business. You purchased all of these goods for your pleasure, not for their future profit. The later items that you bought after your LLC was establish served both purposes (perks of doing what you love).  How should I go about reporting this income for the items I don't have records for how much I purchased them for?  There's nothing you can do. As noted above, these items (if you were to testify in court against the IRS). ""Losses from the sale of personal-use property, such as your home or car, aren't tax deductible."" Source Do I need to indicate 100% of the income because I can't prove that I sold it at a loss? Yes, if you do not have previous records you must claim a 100% capital gain. Source Addition: As JoeTaxpayer has mentioned in the comments, the second source I posted is for stocks and bonds.  So at year begin of 2016, I started selling what I didn't need on eBay and on various forums [January - September]. Because you are not in the business of doing this, you do not need to explain the cost; but you do need to report the income as Gross Income on your 1040. Yes, if you bought a TV three years ago for a $100 and sold it for $50, the IRS would recognize you earning $50.  As these are all personal items, they can not be deducted; regardless of gain or loss. Source Later in the year 2016 (October), I started an LLC (October - December) If these are items that you did not record early in the process of your LLC, then it is reported as a 100% gain as you can not prove any business expenses or costs to acquire associated with it.  Source Refer to above answer.  Refer to above answer.  Conclusion Again, this is a income tax question that is split between business and personal use items. This is not a question of other's assessment of the value of the asset. It is solely based on the instruments of the IRS and their assessment of gains and losses from businesses. As OP does not have the necessary documents to prove otherwise, a cost basis of $0 must be assumed; thus you have a 100% gain on sale." I would suggest at least getting a personal card that you only use for business expenses, even if you don't opt for a business card.  It makes it very clear that expenses on that card are business expenses, and is just more professional.  The same goes for a checking account, if you have one of those.  It makes it easier to defend if you are ever audited, and if you use an accountant or tax preparer.