What bookkeeping records should I keep if I’m self-employed part-time?

Why part-time self-employment still needs solid records

Being self-employed part-time can feel like the best of both worlds: you earn extra income, build a side business, and keep the stability of a main job (or studies, caring responsibilities, or another role). Because it’s “just a side thing,” it’s tempting to treat bookkeeping as optional, or to keep only a vague idea of what came in and what went out. The reality is that part-time self-employment is still a business activity, and good recordkeeping is what turns that activity into something manageable, tax-ready, and less stressful.

Bookkeeping records are not about making your life complicated. They’re about making it simple later. When you keep the right documents and track the right numbers, you can answer basic questions quickly: Did I actually make a profit? Which clients pay on time? Can I afford new equipment? Have I set aside enough for taxes? If you ever need to prove your income to a landlord, a lender, or a benefits office, clean records help there too. And if you’re ever asked questions by a tax authority, clear documentation can make the difference between a quick resolution and a prolonged headache.

This guide breaks down the key bookkeeping records you should keep if you’re self-employed part-time, how long to keep them in practice, and how to organize them so they’re actually useful. It’s designed to be practical, not theory-heavy: you’ll see categories of records, what to capture, why it matters, and common mistakes to avoid.

Start with the “big picture” recordkeeping mindset

Before diving into lists, it helps to decide how you’ll run your bookkeeping day to day. Most people struggle not because bookkeeping is hard, but because it’s inconsistent. You do it in a rush, once every few months, with missing receipts and half-remembered reasons for expenses. A good mindset is: record transactions as close to the time they happen as possible, keep evidence for each transaction, and store everything in a system you can find again.

For part-time self-employment, bookkeeping can be light-touch and still effective. You don’t necessarily need complex accounting software if you have only a few transactions a month. But you do need a consistent place where income, expenses, and supporting documents live. Think of bookkeeping as a chain: your transaction record (what happened) should match your proof (receipt or invoice) and your payment record (bank or card entry). When these link up, you have a complete trail.

Also, separate “business” thinking from “personal” thinking as much as you can. Even if you’re operating as an individual rather than through a company, treating your self-employed activity like a mini-business makes everything clearer. It reduces errors and helps you understand what you’re truly earning after costs and taxes.

The core bookkeeping records you should keep

At minimum, your bookkeeping records should allow you to do three things: calculate your income, identify and support your deductible expenses, and show how money moved in and out of your business activity. The following record categories cover those essentials.

1) Sales and income records

Your income records are the backbone of your bookkeeping. If you’re self-employed part-time, you might earn through freelancing, selling products, online platforms, tutoring, consulting, driving, renting equipment, creating content, or many other routes. Whatever the source, you want a clear record of what you earned, when you earned it, who paid you (or which platform), and what it related to.

Invoices you send

If you invoice clients, keep a copy of every invoice you issue. An invoice should typically include your name or business name, contact details, invoice number, date, description of what you provided, the amount, and payment terms. Even if your clients don’t require formal invoices, creating them is helpful because it standardizes your income records and supports your position if there’s ever a dispute about payment.

In a part-time setup, invoices can also help you track work you’ve completed but haven’t been paid for yet. That matters for managing cash flow and for understanding your true monthly performance. Keep invoices in a chronological folder system or within software that allows easy searching by client name and invoice number.

Payment confirmations and receipts for income

For each invoice (or each sale), keep evidence of payment. This could be bank transaction entries, card payment records, payment processor notifications, or platform payout statements. If you receive cash, you should keep a simple cash receipt log showing date, amount, and what it was for. Cash can be easy to forget, and forgotten income can create mismatches in your records.

Sales records for products

If you sell products rather than services, you’ll want sales summaries. Online marketplaces often provide order histories and payout statements; keep copies (or exports) regularly in case your access changes or the platform limits how far back it shows data. For in-person sales, keep a daily sales log, even if it’s simple. Record total sales, payment types (cash/card), refunds, and any fees taken by card readers or marketplaces.

Refunds, chargebacks, and discounts

Income isn’t always a straight line. If you refund a customer, issue a partial refund, handle a chargeback, or apply discounts, you need to record it. Keep the correspondence or transaction record that shows the refund or adjustment and connect it to the original invoice or sale. This makes your net income accurate and prevents confusion later when bank totals don’t match your “sales” totals.

Grants, incentives, and one-off payments

Some part-time self-employed people receive grants, prizes, sponsorships, or other payments that are not traditional sales. Keep the award letter or agreement and proof of payment. These can be treated differently depending on local rules and circumstances, so having the paperwork helps you categorize them correctly when doing your taxes.

2) Expense records (and proof of each expense)

Expenses reduce your taxable profit (where rules allow) and, more importantly, help you understand whether your side business is actually worth it. You should keep a record of every business expense, plus evidence that supports it.

Receipts and purchase invoices

Keep receipts for anything you buy for business purposes: supplies, equipment, software subscriptions, advertising, training, travel related to work, postage, and so on. Ideally, every expense entry in your bookkeeping should have a matching receipt or invoice that shows the date, supplier, items, and amount. If you only keep bank statements without receipts, you may have trouble proving what the purchase was for if asked later.

Digital receipts count too. Save email confirmations and PDF invoices in a dedicated folder. For paper receipts, consider scanning or photographing them and storing them digitally, because small thermal receipts can fade over time.

Bank and card statements

Statements are useful for cross-checking your records and identifying any missing entries. Even if you track everything in a spreadsheet, reviewing statements monthly helps you catch subscription renewals, platform fees, and small purchases you forgot to record. Statements also show payment dates, which can matter when you’re working out what happened in a given month.

Merchant fees and platform fees

If you use payment processors, marketplaces, or booking platforms, they often take fees before you receive your payout. Keep statements showing gross sales, fees, refunds, and net payout. This helps you record income correctly and ensures fees are not overlooked as expenses. If you only record the net payout as “income,” you might understate both income and expenses, which can distort reporting and make it harder to understand your true margins.

Subscriptions and software

Many part-time businesses rely on tools: design software, scheduling apps, video hosting, cloud storage, music licensing, website hosting, email marketing, or accounting software. Keep invoices or payment receipts for these subscriptions, including renewal dates. It’s easy for subscriptions to quietly expand over time, so tracking them also helps you manage costs.

Phone and internet costs (business use portion)

If you use your phone or home internet partly for business, you may be able to treat a portion of those costs as business-related. Keep your bills and record how you calculated the business-use share. For part-time self-employment, simple, consistent logic is key. If you ever need to justify the proportion, being able to explain your method matters more than having a perfect calculation.

Travel and mileage records

If you travel for business—driving to clients, deliveries, site visits, events, or training—you should keep a travel log. For vehicle use, record the date, start and end locations, purpose, and distance. Keep fuel receipts and maintenance receipts if you use actual vehicle costs, or keep the mileage log if you use a mileage-based method. If you take public transport, keep tickets or digital confirmations.

A common part-time mistake is mixing personal errands with business trips and forgetting to track the business portion. A quick note in your phone immediately after each work-related trip can save hours later.

Meals and entertaining (if applicable)

If you ever buy meals in a business context, keep the receipt and record who it was with and the business purpose. Be careful here: rules can be strict and vary widely, and not all meals are deductible. The record you keep should help you support the purpose, not just the amount.

Professional fees

Keep invoices and payment records for professionals you use: accountants, bookkeepers, lawyers, consultants, coaches, or industry specialists. Also keep proof of membership fees for professional bodies, where relevant. These expenses are easy to document because they usually come with clear invoices—so don’t lose them.

Marketing and advertising

Marketing costs can include online ads, printing, business cards, promotional materials, sponsorships, marketplace listing fees, or influencer collaborations. Keep invoices and screenshots/confirmations where appropriate, especially for online advertising platforms that show charges and campaign dates inside an account dashboard.

Training, courses, and books

If you pay for learning related to your work, keep receipts and course confirmations. Also note what the training was for and how it connects to your business. Clear notes help you categorize the expense properly and remember why you bought it months later.

3) Bank records and cash records

Even for part-time activity, it’s worth thinking carefully about how money flows. If your business money is mixed into your personal bank account, you can still keep good records, but you’ll need extra discipline. If you can open a separate bank account for your self-employed activity, it often makes bookkeeping dramatically easier because every transaction is business-related by default (or at least more so).

Business bank account statements (or separated transaction logs)

If you do have a separate account, keep the statements and reconcile them regularly with your bookkeeping. If you don’t, keep a clear transaction log where you mark which items are business and which are personal. The goal is to make it easy to prove that each “business expense” truly relates to the business and wasn’t a personal purchase.

Cash log

If you accept cash, maintain a cashbook or cash log. It can be simple: date, description, cash in, cash out, and running balance. Record cash deposits into the bank and note when cash was used to buy supplies or cover small expenses. Cash is one of the easiest areas for errors because it bypasses bank records, so keeping a neat cash log protects you.

Petty cash receipts

If you keep a small amount of cash for minor purchases, treat it like petty cash. Keep receipts and record the purpose of each purchase. When you “top up” the petty cash from the bank, record that too.

4) Proof of business assets and equipment purchases

Part-time self-employed people often buy equipment: laptops, cameras, tools, instruments, furniture, or specialist devices. Keep purchase invoices, warranty information, and any finance agreements if you paid in instalments. Also keep a simple asset list that shows what you bought, when you bought it, how much it cost, and whether it’s used solely for business or partly for personal use.

Assets matter because some costs are treated differently than day-to-day expenses. Even if you’re not deep into accounting rules, an asset list makes it easier to deal with tax reporting correctly and to remember what you own for insurance purposes.

5) Inventory and stock records (if you sell goods)

If you sell physical products, your bookkeeping is stronger when you track inventory. You don’t have to run a full warehouse management system for a part-time side hustle, but you should keep records of:

Purchases of stock: invoices from suppliers, shipping costs, and import charges (if any). Keep these together because they help you understand your true cost per unit.

Stock on hand: a periodic count (monthly or quarterly) of what you have left. This helps you spot shrinkage, breakage, or slow-moving items.

Cost of goods sold: if you want to know profitability, you need to know not just sales, but the cost of the items sold. Even a basic spreadsheet can do this.

Returns and damaged stock: record when items are returned, written off, or replaced. This prevents overstating profits and helps you see patterns (for example, if one product has frequent defects).

6) Records for taxes and compliance

Taxes are the big driver of recordkeeping. The exact forms and rules depend on where you live, but the general principle is universal: you should be able to show how you arrived at your reported figures. That means keeping your working papers and supporting documents, not just a final number.

Tax returns and submissions

Keep copies of tax returns you file, including any schedules or supplementary forms. If you submit figures online, save a PDF or screenshot of the submission confirmation. This gives you a history to refer to and makes it easier to answer future questions like “What did I report last year?”

Tax payment records

Keep proof of tax payments: bank confirmations, payment references, and dates. Also keep records of any payments on account, instalments, or adjustments. If you’re part-time self-employed, it’s common to forget exactly what you paid and when—so keeping a folder of payment confirmations avoids confusion.

VAT or sales tax records (if applicable)

If you are registered for VAT or another sales tax system (voluntarily or because you exceeded a threshold), you’ll need additional records: sales invoices showing tax collected, purchase invoices showing tax paid, VAT returns, and evidence for any special treatments (like zero-rated items, exemptions, or reverse charge scenarios). Even if you’re not registered, keep an eye on your turnover with a simple rolling total so you can spot if you’re approaching a registration threshold.

Payroll records (if you employ someone)

Most part-time self-employed people don’t employ staff, but if you do—even casually—you need payroll records, payslips, tax withholdings, pension contributions (if applicable), and employment contracts. If you outsource work to contractors, keep their invoices and payment records too.

7) Records for mixed-use expenses (home office, personal vehicle, shared devices)

Part-time self-employment often overlaps with personal life. You might work from home, use your own laptop, or drive your own car. This is where bookkeeping can get messy. The key record to keep here is not just the bill, but also your method for splitting business and personal use.

Home office records

If you use part of your home for business, keep documents that support the costs you’re allocating: rent statements or mortgage interest statements (where relevant), utility bills, council tax or property tax bills (where relevant), home insurance, and repair invoices. Then keep a simple note explaining how you calculated the business portion, such as based on number of rooms used and time used for business. The goal is clarity and consistency.

Vehicle use records

Keep a mileage log and/or expense receipts, depending on the method you use. Also keep insurance and registration documents if you claim vehicle costs. If you switch methods from one year to another, make a note of why and when.

Shared devices

For items like a laptop or phone used for both personal and business purposes, keep the purchase invoice and a note of your estimated business-use percentage. This helps you handle both expense claims and, if relevant, how you treat the item over time.

8) Contracts, agreements, and business correspondence

Not all bookkeeping records are financial statements and receipts. Contracts and correspondence can be just as important because they explain the “why” behind transactions.

Client contracts and proposals

Keep signed contracts, statements of work, proposals, and engagement letters. These documents show what you agreed to provide, the price, deadlines, scope, and payment terms. If a client disputes an invoice or asks for a refund, having the agreement saved makes the situation easier to manage.

Supplier agreements

If you have ongoing supplier arrangements—like wholesale purchasing, licensing, or service retainers—keep the terms. This helps you confirm whether a charge was expected and whether you’re being billed correctly.

Emails or messages that confirm key decisions

You don’t need to archive every message. But you should keep the messages that confirm scope changes, additional work requests, price changes, cancellations, and approvals. If you’re trying to explain why an invoice amount changed, these records provide context.

9) Loan, finance, and repayment documents (if you borrow for the business)

If you buy equipment on finance, take out a small loan, or use a credit card to fund business costs, keep the loan agreement, repayment schedule, and interest statements. Also keep monthly statements showing repayments. This helps you correctly categorize repayments versus interest and track how much you still owe.

If you use a personal credit card for business spending, keep the statements and ensure you can clearly identify business items. A separate business card can simplify this, but it’s not mandatory if your recordkeeping is disciplined.

10) Insurance and risk-related records

Insurance is a cost, but it’s also a protection. Keep policy documents, renewal notices, and payment receipts for any business-related insurance, such as professional indemnity, public liability, product liability, equipment cover, or cyber insurance. If you ever need to make a claim, you’ll be glad you can quickly find policy details and proof of coverage dates.

How long should you keep bookkeeping records?

Exact retention periods depend on local rules, but a practical approach is: keep records for several years after the end of the tax year they relate to. Even if you’re part-time and your numbers are small, it’s wise to keep digital copies for longer if storage is easy. The point isn’t to hoard everything forever; it’s to protect yourself against questions, amendments, or disputes that may arise later.

In practice, most part-time self-employed people find it easiest to keep a digital archive indefinitely (or at least for a long period), especially for tax returns, major equipment purchases, and contracts. Receipts and invoices can be stored compactly as PDFs or photos. If you do keep paper copies, keep them in a dry, organized folder system and scan anything printed on heat-sensitive paper.

What your bookkeeping system should capture (even if it’s just a spreadsheet)

No matter what tool you use—spreadsheet, app, or accounting software—make sure your transaction records include consistent fields. For a simple, effective system, aim to capture:

Date of transaction: ideally the invoice date and payment date if they differ.

Description: what it was for, in plain language you’ll understand later.

Category: income type or expense type (for example: “design services,” “advertising,” “software,” “travel”).

Supplier or client: who you paid or who paid you.

Gross amount and fees: especially if platforms take fees before payout.

Payment method: bank transfer, card, cash, platform payout.

Reference: invoice number, receipt number, order ID, or transaction ID.

Link to evidence: a filename or folder path for the receipt/invoice, or an attachment in your software.

When these fields are consistent, year-end reporting becomes a sorting and summing exercise, not a detective story.

Simple folder organization that actually works

If you’re not using accounting software that stores documents, a folder system can do the job. The secret is to make it predictable. Here is a structure many part-time self-employed people find easy:

01 Income: invoices issued, sales reports, platform payout statements.

02 Expenses: receipts and supplier invoices, organized by month or category.

03 Banking: bank statements, card statements, payment confirmations.

04 Tax: returns, submissions, tax payments, calculations.

05 Contracts: client agreements, supplier agreements, key correspondence.

06 Assets: equipment purchases, warranties, finance agreements, asset list.

Within each folder, name files consistently. For example: “2026-01-15_ClientName_Invoice_004.pdf” or “2026-01-20_Adobe_Subscription_Invoice.pdf”. The date-first naming convention keeps items in chronological order automatically.

Recordkeeping for common part-time self-employed scenarios

Different side businesses generate different records. Here are a few common scenarios and what to watch for.

Freelancers and consultants

Keep proposals, contracts, timesheets (if you bill by time), invoices, and client communication that confirms scope changes. Track expenses like software, coworking days, travel, and professional subscriptions. If you do occasional subcontracting, keep those invoices and note which client project they relate to.

Creators, influencers, and online sellers

Platforms often provide detailed statements that can change over time. Export payout data regularly. Keep records of sponsorship agreements, affiliate income reports, ad revenue statements, and expenses like equipment, editing software, props, and studio costs. If you receive gifted products, keep a record of what you received and why, because it can affect how you interpret income in some contexts.

Trades, repair work, and in-person services

Cash payments and material purchases are the big risks. Keep a cash log, issue receipts where practical, and keep supplier invoices for materials. Track mileage and travel time if you move between jobs. Keep safety certification and insurance documents together with your business records.

Tutoring, coaching, and lessons

Keep lesson schedules, invoices or payment receipts, and any platform statements if you use a marketplace. If you rent space (a room, studio, or facility), keep rental invoices. If you buy teaching resources, record them and keep receipts. Clear records also help you evaluate which services or subjects are most profitable.

Side businesses alongside employment

If you also have a regular job, it’s even more important to separate personal and business finances because your self-employed activity can get lost among salary payments and personal spending. Consider a separate bank account, even if you keep the rest of your setup simple.

Common bookkeeping mistakes part-time self-employed people make

Avoiding a few classic errors will improve your records immediately.

Not recording small expenses

Small expenses add up: app subscriptions, domain renewals, parking fees, stationery, postage. If you skip them, your profit looks bigger than it is, and you lose visibility into your true cost of doing business.

Failing to keep proof

A bank statement line that says “SHOP” or “ONLINE PAYMENT” isn’t proof of what you bought or why it was business-related. Save receipts as you go. If you can’t get a receipt, write a note with the date, amount, and purpose and keep it with your records.

Mixing personal and business spending without a system

It’s not illegal to use a personal account for business, but it makes your bookkeeping harder. If you do mix, you need a reliable method to tag business transactions and keep evidence. Otherwise, you’ll end up missing deductible expenses or accidentally including personal spending.

Ignoring platform fees and taxes withheld

Some platforms deduct fees before payout, and some may withhold taxes or other charges depending on your situation. If you only record the amount you receive, your records won’t tell the full story. Always capture gross amounts, fees, and net payout where possible.

Not setting aside money for taxes

This is less a “record” and more a discipline, but your bookkeeping should support it. When your income comes in, it helps to record a “tax set-aside” figure or transfer money to a separate savings pot. Keeping a record of these transfers helps you avoid spending money that will later be due.

Doing everything at year-end

Trying to reconstruct a year of transactions in one weekend is stressful and error-prone. A monthly routine—download statements, file receipts, update your income and expense log—keeps things manageable. Part-time self-employment is supposed to fit around your life, not take it over.

A practical monthly bookkeeping checklist

If you want something you can actually follow, here’s a simple monthly checklist that covers most part-time self-employed needs:

1) Collect all receipts and invoices from the month, including digital ones.

2) Update your income log: invoices issued, payments received, platform payouts.

3) Update your expense log: categorize each expense and attach/save proof.

4) Reconcile with your bank and card statements: ensure every business transaction is recorded and explained.

5) Update mileage logs and any cash records.

6) Review unpaid invoices and follow up where needed.

7) Estimate profit for the month and transfer a portion to a tax set-aside account (if you use one).

This routine can take less than an hour once you get used to it, especially if you keep documents organized as you go.

When to consider using bookkeeping software

For some part-time self-employed people, a spreadsheet is enough. For others, software saves time and reduces mistakes. You might consider software if you:

Send invoices regularly and want automatic reminders or templates.

Have many transactions through platforms, payment processors, or multiple bank accounts.

Need to track inventory or projects.

Want to attach receipts to transactions and search easily.

Plan to grow your side business and want a system that scales.

Even if you stay with a spreadsheet, adopting software later is easier if you’ve kept clean records from the start.

How to make your records “audit-ready” without becoming obsessive

You don’t need to live in fear of being questioned, but you do want your records to be defensible. The simplest way to be “audit-ready” is to ensure every transaction has a clear story: what it was, why it was business-related, and evidence that it happened.

For income, that story is typically: contract or agreement → invoice or sale record → payment record. For expenses, it’s: receipt or supplier invoice → payment record → note explaining business purpose (especially for mixed-use items). If you can produce that chain quickly, your bookkeeping is strong.

Final thoughts: keep it simple, consistent, and complete

If you’re self-employed part-time, your bookkeeping doesn’t need to be complicated, but it does need to be consistent. The most important records to keep are your income documents (invoices, sales reports, payout statements), your expense proof (receipts and supplier invoices), your bank and payment records (statements and confirmations), and the agreements that explain what you’re doing (contracts and key correspondence). Add logs for mileage and cash if those apply to you, and keep an asset list if you buy equipment.

Good bookkeeping gives you more than tax compliance. It gives you clarity. You’ll know whether your side business is profitable, where your money goes, which work is worth your time, and how to plan for growth without unpleasant surprises. Most importantly, it helps your part-time self-employment feel sustainable—something you can manage confidently alongside everything else in your life.