Christy;
In 25 years of adversarial tax practice including audits, appeals and tax courts, I’ve almost never seen a legitimate business expense that would be permitted in an entity (e.g.: LLC) that would be prohibited for a Schedule ‘C’ business.
The IRS uses the terms ‘substance over form’; the auditors consider the true nature of income and expenses, rather than just what might be written on a piece of paper. The ‘substance over form’ principle applies equally to inclusion and exclusion of both income and expense.
If an expense is reasonable and necessary for the production of income, it may be deducted from business income. Leases for office equipment or vehicles are equally deductible regardless of business structure. Interest related to business expenses is also deductible.
An LLC can be taxed as a disregarded entity (which is reported on Schedule ‘C’), partnership, ‘C’ corporation or ‘S’ corporation. Tax treatment and filing requirements vary upon which tax structure is elected by the taxpayer.
However, I do agree with your point of separating business checking/finance, even for a Schedule ‘C’ business. A separate checking account, either in the name of the individual or the DBA, simplifies recordkeeping at tax time or in case of audit/examination. Likewise, using a specific credit card exclusively for business is an excellent practice.
Keeping good written records of out-of-pocket expenses (gas/toll/parking/etc.) and a mileage log is a practice that can save lots time and money at tax time - even more so if called before a tax agency. Reimbursing expenses by check (from the business/DBA account to one’s personal account) after putting on file an expense report (a written summary, with receipts if possible) is also a great way to keep the ‘books’ segregated.
A individual can use a secondary TIN (the IRS allows a taxpayer to request a single secondary TIN so they don’t have to give out their SS#; the request uses IRS Form SS-4, which can be filed online) to avoid confusion. If the taxpayer files multiple Schedules ‘C’ (for multiple businesses), they are still limited to a single secondary TIN.
FYI, I’ve seen significantly-sized businesses with dozens of employees and millions of dollars in revenue reported on a Schedule ‘C’, although it’s not that common.
There are a few exceptions to the rule, however. For example, the QBI/IRC 199A deduction, which is available on pass-through entities (partnerships, ‘S’ corporations) allows for the deduction of up to 20% of qualified business income. Certain other exceptions do exist, but many are not particularly relevant (or practical to pursue) until income becomes substantial.
As always, you should contact credentialed and experienced legal and/or tax professionals, admitted to practice in your state, should you want to explore the advantages and disadvantages of creating a business entity.
Hope this is useful.
HWB.