Guide
How to keep records for taxes as a self employed mechanic
Good records are not built in the spring. They are built on the days the work happens, by systems that survive being tired.
The short answer
Keep two things separate and most of the difficulty disappears: the money and the paperwork. Put every dollar the business takes in and every dollar it spends through one account that is used for nothing else, and the account statement becomes a complete list of what happened, which is the hardest part of the whole exercise to reconstruct later.
Then capture the four kinds of record a repair week generates. What you charged and whether it was paid. What you spent, with the receipt attached to the thing it was for. Where you drove and why. And the documents that support the unusual items, which are the ones that get questioned precisely because they are unusual.
Do the capture at the moment, not at the weekend. A photograph of a receipt taken standing at the parts counter takes seconds and always happens; a shoebox sorted on a Sunday depends on a version of you that is not tired, and that version does not reliably exist.
This page states no tax rate, no threshold, no deadline, no retention period and no rule about what can be deducted. Nobody writing it is a tax preparer, the rules differ by state and by how your business is set up, and they change. The primary sources are the IRS, published at irs.gov, and your own state revenue or taxation department. For anything that turns on your specific situation, an hour with a qualified preparer costs less than any of the ways this goes wrong.
Records are built during the week, not found afterwards
The reason most self employed record keeping fails is not laziness, it is timing. It is designed as a task to be done later, and later is when the information has already started disappearing. A card transaction from four months ago is a merchant name and an amount, and nothing in it says which job it belonged to or whether it was for the business at all.
Anything captured at the moment carries context for free. The receipt photographed at the counter still knows what you were buying and why. The note written while the van is still on the driveway still knows which customer it was. Neither of those facts survives a month unaided.
This is why the useful question is not which system to use but which habit survives a bad day. A method that works when you are behind, wet and hungry is worth more than a better method that only works on a quiet Tuesday.
Every job has two sides and both of them need a record
Money in is the side people remember, because it is the side with the invoice. Money out is the side that decides what the year actually looks like, and it is much easier to lose: parts bought on a personal card, fuel paid for in cash, a tool bought on the way to a job, a phone bill nobody thought of as a business expense.
The two sides also need to be connected, not just collected. A parts receipt is more useful when it is attached to the job it was bought for, because that is what makes it possible later to say which jobs actually made money and which only looked as if they did.
That connection is worth building for reasons that have nothing to do with tax. The guide in this cluster on what to charge as a mobile mechanic depends entirely on knowing what a job kept rather than what it invoiced, and both questions are answered by the same records.
Where to check instead of guessing
Tax questions have real answers, and they live in specific places rather than in general knowledge. The IRS publishes its own guidance for small businesses and self employed people at irs.gov, including material on what records a business is expected to keep, and the search there is the fastest route to whichever question you actually have.
Your state is a separate matter with a separate authority. State revenue or taxation departments set their own requirements, and states differ from each other substantially. If your work involves sales tax on parts or on labour, that is a state question before it is a federal one, and the answer comes from your own state department rather than from any national summary.
Where a question turns on your particular circumstances, a qualified preparer is the answer rather than more reading. The point of good records is that this conversation becomes short and cheap: somebody who is handed a clear year charges less than somebody who has to reconstruct one, and they can answer questions that a page like this one deliberately will not.
Treat anything you read online about tax, including this page, as a prompt to check rather than as a conclusion. Rules change between years, they differ by state, and they differ by how a business is structured, which means a confident answer written by a stranger is the least reliable thing in the whole subject.
The records a repair week produces, and what each one proves
A description of the documents an ordinary week generates and what each is evidence of. This is not a list of what anybody is required to keep, and it does not say how long any of it should be held; both of those are questions for the IRS, your state department and your preparer.
Invoices and estimates. These are the record of what you charged and what was agreed, and they are the backbone of the income side. Sequential numbering matters more than it looks: a numbered series makes a gap visible, and a gap is the only way to notice a job that was done and never billed.
Payment records. What was actually received, when, and by what means. This is a different fact from what was invoiced, and the difference between them is the money you are owed. Card settlements, transfers and cash all need to land in the same picture, and cash is the one that needs deliberate effort.
Parts purchases. The supplier invoice or receipt, ideally connected to the job it was for. Two things make this side of the record fail: buying on a personal card in a hurry, and buying several jobs worth of parts on one receipt so that nothing can be attributed afterwards.
Vehicle and travel records. Where you went, why, and how far. For a mobile business this is one of the largest categories in the year and also the one that cannot be reconstructed after the fact, because your memory of a Tuesday in March is not going to produce a route. This has its own guide in this cluster on mileage records for mechanics.
Tools and larger equipment. Big purchases are treated differently from consumables, and how they are treated is exactly the sort of thing that varies and that this page will not attempt to answer. What is within your control is keeping the invoice, the date and what was bought, which is what lets somebody qualified answer it correctly.
Running costs of the business itself. Insurance, phone, software, licensing, professional fees, workwear, waste disposal. These are individually small, collectively significant, and almost always the category people underrecord, because none of them feels like a business expense in the moment.
Bank and card statements. The spine that everything else attaches to. A statement is the only document that is guaranteed to be complete, which is why a dedicated account matters so much: it converts a memory exercise into a reading exercise.
Anything unusual. A vehicle bought or sold, an insurance settlement, a bad debt written off, work done for a business that sends its own paperwork, a piece of equipment financed rather than bought. Unusual items attract questions, so they are the ones where a note written at the time saying what happened is worth the most.
Notice what the list is doing. Each item is evidence of a specific fact, and the reason to keep it is that the fact will otherwise be reconstructed from memory by somebody with an incentive to be optimistic. Records are not paperwork for its own sake, they are the difference between a return based on what happened and a return based on what you think happened.
Separate the money before you try to separate the paperwork
If you do only one thing from this page, do this one. Run the business through its own bank account and its own card, and use them for nothing else. Everything downstream gets easier and several problems disappear entirely.
The first thing it fixes is completeness. Mixed accounts mean the year has to be assembled by remembering which transactions were business, and that process both misses expenses and includes things it should not. A dedicated account is a finished list on the day the year ends.
The second is speed. Sorting a mixed account is the single largest cause of the spring in which nothing else gets done, and it is also what makes a preparer expensive: they are charging for hours of untangling that need not have existed.
The third is that it makes the business visible while the year is still happening. When one account holds everything, the balance is a real signal rather than a mixture of a van payment and a grocery shop, and questions like whether a quiet month was actually quiet become answerable in seconds.
The habit that goes with it is one sentence long: if the business spends it, it comes out of the business account, and if a customer pays it, it goes into the business account. The exceptions are what cause the trouble, so where you genuinely have to pay for something personally, move the money afterwards rather than leaving a note for later.
Cash needs a deliberate answer, because it is the one thing an account does not capture on its own. Whatever your habit is, it should end with the cash reaching the business account and a record saying which job it came from. Cash that goes straight into a pocket is a payment that leaves no trace anywhere, and the person it hurts most is you, at the point where you are trying to prove your own income to a lender or work out what the year really earned.
None of this is a statement about what any rule requires, and whether a separate account is necessary rather than merely sensible depends on how your business is set up, which is a question for a preparer. It is on this page because it is the change that makes every other record keeping habit possible, and because the people who never manage the rest are almost always the people who skipped it.
Where the short answer stops being the answer
Every rule on this page has a situation it does not survive. Here are the ones worth knowing about before you meet them.
A lot of your customers pay in cash
Give cash the same treatment as everything else and give it a fixed routine, because it is the only category with no automatic trail. Receipt written at the time, payment recorded against the job, money into the business account on a regular schedule rather than when you remember.
The reason to be rigorous here is not only compliance. Unrecorded income is invisible when you want a loan, invisible when you are trying to work out whether a rate change worked, and invisible to the arithmetic in the pricing guide, so it makes your own business harder to run.
The van and the phone are used for personal things too
Mixed use items are treated in a particular way and this page is not going to describe it, because that is precisely the kind of rule that varies and changes. What you can do without any tax knowledge is keep the underlying facts: what the item cost, and a contemporaneous record of the business use.
For the vehicle that means a travel record kept as you go. For the phone it usually means keeping the bills. Those records let a preparer apply whatever the correct treatment is, and without them nobody can, whatever the rule turns out to be.
You do work for a business that sends you its own paperwork
Keep your record of the work as well as theirs. Your invoice, your record of what was paid and when, and whatever document they issue are three different things, and reconciling them is a great deal easier while the job is recent.
Where a business customer sends paperwork that does not match what you invoiced, raise it immediately rather than filing it. A discrepancy resolved in the same month is an email; the same discrepancy found a year later is somebody trying to remember a job.
Part of your year was employed and part of it was self employed
Keep the two entirely separate in your own records, including the dates the change happened. Mixing them is the most common way a year becomes confusing to reconstruct, and the confusion is completely avoidable with a line drawn on a date.
This is also a situation worth taking to a preparer rather than working out yourself, because a year with two kinds of income in it has more moving parts than either kind alone.
When it has already gone wrong
Most people find a page like this after the fact rather than before it. This part is for them.
The year is over and your records are a box and a bank app
Work backwards from the bank statements rather than forwards from the receipts, because the statements are the only complete list you have. Go through them line by line, mark what was business, and then attach the receipts you can find to the lines they belong to. Anything with no receipt still happened and is still worth noting with what you remember about it.
Then do the one thing that stops it recurring, which is opening a separate account and starting now rather than at the beginning of a year. A clean second half is worth more than a resolution about next January.
You cannot tell which transactions were business and which were personal
Go through the statement with the calendar and the job records side by side. A transaction next to a job on the same day is usually explicable; one on a day you did not work usually is not. Where you genuinely cannot tell, say so rather than guessing in your own favour, and let a preparer decide how to handle it.
Expect this to take a long time and let that be the argument for the separate account. It is the single most expensive habit to lack and the cheapest one to fix.
You lost the phone with all the receipt photographs on it
Most of it is recoverable if you start straight away. Suppliers can reissue invoices, card and bank statements show the transactions, and a parts factor can usually print a full account history. The reconstruction is far easier now than it will be in six months.
Then change where the photographs live. Anything that exists only on a phone is one drop away from gone, and the fix is that receipts land somewhere that is not the device you carry into a wheel arch.
Questions
What records does a self employed mechanic need to keep?
What anybody is required to keep is a question for the IRS at irs.gov and for your state revenue department, and this page does not answer it. What a repair business actually generates is invoices and estimates, payment records, parts purchases, travel records, tool and equipment purchases, running costs, bank statements, and documentation of anything unusual. Keeping those puts you in a position to answer whatever the requirement turns out to be.
How long should I keep receipts and invoices?
This page does not state a period, because retention periods depend on the situation and are set by the IRS and by your state rather than by convention. The IRS publishes guidance on this at irs.gov and your state revenue department publishes its own. Ask your preparer once and then apply the answer consistently, since a rule you follow is worth more than a longer one you do not.
Do I need a separate bank account for my mechanic business?
Whether it is required depends on how your business is set up and is a question for a preparer. Whether it is worth doing is not really in question: it makes the year complete without effort, it removes the largest and most tedious task from the end of it, and it is the habit that makes every other record keeping habit possible.
Can I deduct my van, my tools or my phone?
This page states no deduction rules at all. What can be claimed, and how it is treated, depends on the item, on how the business is structured and on rules that change, which makes it exactly the kind of question a stranger should not answer for you. The IRS publishes the federal position at irs.gov, your state department publishes its own, and a preparer can apply both to your situation. What you can do regardless is keep the purchase records and a contemporaneous note of business use, because without those nobody can claim anything correctly.
Do I need accounting software to keep records?
No. Plenty of one van businesses run on a dedicated bank account, a numbered invoice book and a folder of photographed receipts, and that is genuinely sufficient. Software helps mainly with two things: the arithmetic, and making the records exist at the moment rather than later. If a tool does not survive a bad day it is not helping, whatever it costs.