What bookkeeping records should I keep if I only have one or two clients?

Why bookkeeping still matters when you only have one or two clients

When you only have one or two clients, it’s tempting to assume bookkeeping can be “simple enough” to live in your head, your bank app, or a few scattered invoices. And in a day-to-day sense, that might feel true—until tax time arrives, a client questions a charge, a bank asks for proof of income, or you realize you need to understand whether you’re actually making money after expenses.

Bookkeeping is less about the number of clients and more about the quality of your records. Even with a tiny client list, your finances can get complicated quickly: different payment terms, partial payments, refunds, software subscriptions, travel costs, currency conversions, sales tax or VAT rules, contractor payments, and equipment purchases are all common. Good records protect you, reduce stress, and give you confidence that you’re pricing correctly and meeting your obligations.

The goal is not to create bureaucracy. The goal is to keep a set of records that are complete, easy to find, and consistent—so that you can answer questions like: What did I earn? When did I get paid? What did I spend? What can I claim? Do I owe tax? And can I prove it?

Start with the “minimum viable” bookkeeping system

If you have one or two clients, you can keep bookkeeping lean while still meeting best practices. Think of it as a small system with a few moving parts:

1) A way to record money in and money out (a spreadsheet or bookkeeping software). 2) A folder structure for documents (invoices, receipts, contracts). 3) A routine (weekly or monthly) to reconcile, file documents, and review.

This article walks through which bookkeeping records matter most, what they should include, and practical ways to store them.

Core record #1: Sales records (invoices, receipts issued, and sales summaries)

Your sales records show what you charged and why. Even if you have only one or two clients, your sales documentation should be consistent and professional because it’s often the foundation for income reporting, tax compliance, and client disputes.

Invoices you issue

If you invoice clients, keep a copy of every invoice. Each invoice should include key details that make it unambiguous:

Essential invoice fields: invoice number, issue date, your business name and address (and any required registration details), client name and address, description of services, quantity or hours, rate, subtotal, taxes (if applicable), total, currency, payment terms, due date, and payment instructions. If you use purchase orders, reference the PO number.

For bookkeeping, it’s important that invoice numbers are unique and sequential (or at least systematically unique). Gaps can happen, but you should be able to explain them (for example, a voided invoice).

Receipts or confirmations you provide

In some businesses, you provide a receipt instead of an invoice, or you provide both. For example, if a client pays immediately, you might issue a receipt showing date paid, amount, method, and what it was for. Keep copies of those receipts as well.

Sales summaries

Even with a small client base, it helps to keep a simple sales summary showing totals by month, by client, and by service type. This can be built from your invoice list or generated by bookkeeping software. It gives you quick answers for forecasting and tax planning. It also helps you spot a risky situation: if one client is most of your income, losing them could severely impact cash flow.

Core record #2: Proof of payment and income (bank deposits, payment processor reports)

Invoices show what you billed. Proof of payment shows what you actually received. That difference matters because clients may pay late, partially pay, overpay, pay in multiple installments, or pay with fees deducted.

Business bank account statements

If possible, use a dedicated business bank account. If that’s not feasible, keep your transactions clearly separated and documented. In either case, download and store bank statements regularly (monthly is typical). Statements are strong evidence for income and expenses and are central to reconciliation.

Payment processor statements and reports

If clients pay via PayPal, Stripe, Wise, Square, or another processor, keep the monthly statements and transaction exports. Payment processors often deduct fees or hold funds temporarily, which means the net deposit to your bank may not match the gross invoice amount. Your records should track:

Gross received (what the client paid), fees (processor charges), net deposit (what you actually received), and the date of each event.

Remittance advice and payment confirmations

Some clients send remittance advice (a note showing which invoices were paid) or you might have email confirmations for transfers. Save these, especially when payments cover multiple invoices or when the client’s payment reference is unclear.

Core record #3: Expense records (receipts, bills, and proofs of purchase)

Expenses reduce taxable profit (where allowed) and show what it costs you to operate. Even a solo freelancer with one client might have dozens of expense categories: software, internet, phone, laptop, equipment, subscriptions, professional services, training, travel, marketing, and insurance.

Receipts for business purchases

Keep receipts for everything you plan to claim as a business expense. A good receipt generally shows: supplier name, date, item description, amount, and taxes (if any). If the receipt is missing details, a bank transaction alone might not be enough. In that case, keep a screenshot of the order confirmation, email invoice, or a note explaining the business purpose.

Bills from vendors and service providers

For recurring costs like software subscriptions, cloud storage, coworking, internet service, accounting fees, or insurance, keep vendor bills and invoices. Many vendors provide PDF invoices in an online portal; download them periodically so you’re not dependent on access later.

Proof of payment

Receipts show the purchase happened; proof of payment shows it was paid. Often the receipt itself indicates payment. If not, keep the bank record or processor confirmation. When questioned, having both makes your records much stronger.

Expense categorization notes

With one or two clients, you might think categorizing is overkill. But categorization is how you learn what drives your costs and whether your pricing covers them. Keep a record of how you classify expenses (for example: “Software,” “Office,” “Travel,” “Professional fees”). Consistency is more important than perfection.

Core record #4: Client contracts, statements of work, and scope documentation

Bookkeeping isn’t only numbers. The documents that define your business relationship are part of your financial recordkeeping because they explain why an invoice was issued and what you were obligated to deliver.

Signed contracts and agreements

Store signed contracts, master service agreements, independent contractor agreements, and any amendments. These documents establish key terms such as payment schedules, late fees, ownership of work, confidentiality, and termination rights.

Statements of work (SOWs) and proposals

If you do project work, keep the proposal and SOW that details deliverables, milestones, and pricing. This becomes critical when there are change requests or disputes about what was included.

Change orders and scope changes

With a small number of clients, scope creep can be a major profit leak. Keep written records of scope changes, including emails that confirm new requirements and fees. This protects your profitability and helps you reconcile why an invoice changed from the original plan.

Core record #5: Accounts receivable tracking (who owes you, what’s overdue)

Accounts receivable is simply money clients owe you. If you have one or two clients, this is both easier and more dangerous: if one client delays payment, your entire cash flow can be affected.

Aging report or overdue list

Maintain a list of outstanding invoices with invoice date, due date, amount, and status (unpaid, partially paid, paid). If you use bookkeeping software, it will generate this. If you use a spreadsheet, a simple table works well.

Collections and follow-up notes

Keep notes on follow-ups: dates you sent reminders, any promises made by the client, and revised payment dates. This is useful if you ever need to escalate or if you simply want to measure how long clients take to pay.

Core record #6: Accounts payable tracking (what you owe and when)

Accounts payable is money you owe vendors or contractors. Even if you rarely buy on credit, you likely have invoices from suppliers or annual subscriptions that hit at specific times. Tracking these prevents surprises and helps cash flow planning.

Unpaid bills list

Keep a list of bills with due dates and amounts. For one-person businesses, this can be very simple. The main goal is to avoid late fees and ensure you don’t forget an important payment like insurance or licensing.

Core record #7: Mileage, travel, and business-use logs

Travel and vehicle-related deductions (where permitted) are areas where records matter a lot. Tax authorities often scrutinize these because personal and business use can blur together.

Mileage log

If you use a vehicle for business, keep a mileage log that records date, starting point, destination, business purpose, and miles or kilometers. A phone app can help, but a spreadsheet is fine if it’s accurate and updated.

Travel expense documentation

For travel, keep itineraries, receipts for transport, lodging, and meals (if allowable), and a note of the business purpose. If you travel for a client project, keep the email or contract clause that required it.

Home office records (if relevant)

If you work from home and claim a home office deduction (where allowed), keep records that support business use. This may include a calculation of the portion of your home used for work, rent or mortgage interest statements, utility bills, and evidence that the space is used for business. The exact requirements vary by jurisdiction, but the principle is consistent: document the basis of your claim and keep supporting bills.

Core record #8: Payroll, subcontractor, and freelancer payment records

Even with one or two clients, you may hire help: a designer, developer, assistant, editor, or bookkeeper. Once you pay others, you need a clean record of those payments.

Contractor invoices and agreements

Keep copies of contractor invoices, contracts, and statements of work. They should show what you paid for and when. If you’re paying international contractors, keep records of currency conversion and transfer fees.

Payment confirmations

Store proofs of payment for contractors, such as bank transfers or payment processor confirmations. Make sure the payment can be linked back to the contractor invoice.

Employment or payroll records (if applicable)

If you have employees, you’ll need payroll records, payslips, tax withholdings, and any filings required by your local rules. This can become complex quickly, so many small businesses outsource it. Regardless, the records should be retained and organized.

Core record #9: Asset and equipment records (laptops, cameras, furniture, software licenses)

Assets are items that provide value over time, such as a computer, tablet, camera, or office furniture. Some purchases are treated differently from regular expenses for tax and accounting purposes.

Asset register

Maintain a simple asset register with the item name, purchase date, purchase price, vendor, and how it’s used in the business. If you later sell or dispose of the asset, record the date and proceeds. Even if you don’t do formal depreciation schedules, having an asset list helps you keep track of what you own and supports claims.

Warranty and insurance documents

Keep warranties, proof of ownership, and insurance documents for major equipment. If something is stolen or damaged, your ability to claim often depends on having paperwork that proves you owned it and shows its value.

Core record #10: Tax records (returns, filings, and calculations)

Tax records are where bookkeeping becomes “real.” Your bookkeeping records feed your tax filings, and your tax filings become records you should retain.

Tax returns and supporting schedules

Keep copies of filed tax returns and any schedules, attachments, or calculations. These are essential if you need to reference prior years, respond to questions, or apply for financing.

Sales tax/VAT records (if applicable)

If you charge sales tax or VAT, keep records of: taxable and non-taxable sales, tax collected, tax paid on purchases (if reclaimable), and the filings you submitted. Store evidence of why certain sales were treated a certain way (for example, client location or service type) if your rules require it.

Estimated tax and payment records

If you make estimated payments during the year, keep proof of those payments and note which period they relate to. This helps you avoid double-paying or underpaying and makes year-end reconciliation easier.

Year-end summaries

At the end of each year, produce and store a simple summary: total income, total expenses by category, net profit, taxes paid, and any significant changes (new client, price changes, major equipment purchase). This becomes a handy narrative when you look back later.

Core record #11: Bank reconciliation records

Reconciliation means checking that what’s in your bookkeeping records matches what happened in your bank and payment processor accounts. It is one of the most important habits you can build because it catches mistakes early.

Reconciliation reports or notes

If you use bookkeeping software, save reconciliation reports (monthly or quarterly). If you use a spreadsheet, keep a monthly checklist that indicates you matched each transaction to an invoice, receipt, or category.

Handling mismatches

When the bank deposit doesn’t match your invoice, don’t ignore it. The mismatch could be fees, exchange rates, partial payments, or errors. Keep a short note explaining the difference and link it to relevant documents. This is especially important when you have few clients because each payment tends to be large relative to your total income.

Core record #12: Communications that affect money (emails, approvals, disputes)

Not every email belongs in bookkeeping, but some communications are effectively financial records because they confirm approvals, pricing, or payment terms.

Written approvals and sign-offs

If a client approves an estimate, a milestone, an extra charge, or a revised scope in writing, keep that message. Store it in the client folder with the related invoice or project documentation.

Dispute documentation

If a client disputes an invoice, keep the dispute thread, any evidence you provided, and the final resolution. If you negotiated a discount, partial refund, or credit note, document it and ensure your bookkeeping records reflect it correctly.

What records look like in practice: a simple list you can follow

If you want a straightforward checklist, here’s what most one-to-two-client businesses should retain in an organized way:

Income: invoices issued (PDF copies), receipts issued, bank statements, payment processor reports, remittance advice, deposit confirmations, credit notes or refunds, and a monthly income summary.

Expenses: receipts, vendor invoices, subscription invoices, proofs of payment, expense categorization list, and a monthly expense summary.

Client relationship documents: contracts, SOWs, proposals, scope change approvals, and key payment-term communications.

Tax and compliance: tax returns, sales tax/VAT filings (if applicable), proof of tax payments, year-end summaries, and any registration documents required for your business.

Operational logs: mileage logs, travel logs, home office calculation support, and an asset register for equipment.

How to organize your records so you can find them fast

Good records are only useful if you can locate them quickly. With one or two clients, you can build a clean structure that stays manageable for years.

Create a consistent folder structure

A simple approach is a top-level folder per year, then subfolders for income, expenses, tax, and clients. For example:

2026 → Income, Expenses, Tax, Clients, Assets

Within Clients, create a folder for each client and then subfolders like Contracts, Invoices, Scope, Payments.

Use a naming convention for files

File naming is one of the easiest ways to stay organized. A consistent pattern might include the date, vendor or client, and amount. For example:

2026-02-14_ClientName_INV-1043_1500.00.pdf

2026-02-15_Adobe_Subscription_52.99.pdf

2026-03-01_Stripe_PayoutReport_February.pdf

When you have only one or two clients, you’ll likely remember what something is—until you don’t. The naming convention future-proofs your system.

Keep digital copies even if you have paper

Paper receipts fade, get lost, and are hard to search. Snap photos or scan receipts and store them digitally. If your local rules allow digital copies, it can drastically reduce clutter and make your life easier.

How long should you keep bookkeeping records?

Retention periods vary by location and situation. A safe general approach is to keep records for multiple years after the end of the tax year they relate to, and longer for anything related to assets, major contracts, or long-term disputes.

Instead of aiming for the minimum, many small businesses keep digital records for a longer period because storage is cheap and the downside of not having records can be costly. If you’re unsure of your local requirement, consider keeping a longer archive and maintaining a clear year-based folder structure so older records don’t get in the way.

Common mistakes when you only have one or two clients

Small client lists create a few predictable traps. Avoiding these will improve your recordkeeping immediately.

Mixing personal and business transactions

When everything runs through one account, it’s harder to prove what was business versus personal. If you can, use a separate account for business. If you can’t, keep meticulous notes and consider dedicating one card to business purchases only.

Relying on bank statements alone

A bank statement shows money moving, but often not the “why.” You still need invoices and receipts that document what the transaction represents. Bank statements are necessary; they are not sufficient by themselves.

Not tracking fees and withheld amounts

Payment processors and platforms can deduct fees, hold funds, and create timing differences between payment date and deposit date. If you don’t record gross and fees correctly, your income can look wrong and reconciliations become frustrating.

Forgetting to document scope changes

With one main client, it’s easy to agree to “just a few extra things.” Without written scope updates, you can undercharge, lose track of time, or face disputes. Written confirmations are a key financial record.

Waiting until year-end

Year-end catch-up bookkeeping is stressful and error-prone. A small weekly routine takes far less time than a yearly scramble.

A simple monthly routine for staying on top of records

If you want a routine that works for one- or two-client businesses, keep it predictable:

Weekly (10–20 minutes): file new receipts and invoices, update your income/expense tracker, and note any scope changes that affect billing.

Monthly (30–60 minutes): download bank and processor statements, reconcile transactions, review outstanding invoices and bills, and back up your records.

Quarterly (optional but helpful): review profitability, set aside tax estimates, check subscription creep, and ensure your pricing still makes sense.

Spreadsheets vs bookkeeping software: what’s enough with one or two clients?

You can manage bookkeeping with either a spreadsheet or accounting software. The best choice depends on how complex your payments and expenses are and how much automation you want.

When a spreadsheet is usually enough

A spreadsheet can work if you: issue few invoices, have straightforward payments, limited expenses, and no sales tax/VAT complexity. If you choose a spreadsheet, include columns for date, description, category, client, invoice number, gross amount, fees, net amount, payment method, and notes. The key is consistency and reconciliation.

When software becomes worth it

Software is often worth it if you: deal with multiple currencies, need automated invoice reminders, want bank feed imports, have more expense volume, need tax tracking, or want clean reports without manual formulas. Software can also make it easier to attach receipts directly to transactions.

Special considerations for one-client businesses

If most or all of your income comes from one client, treat recordkeeping as risk management.

Keep extra-strong documentation

When one client dominates your revenue, any dispute is a major threat. Maintain clear contracts, scope documents, time logs (if you bill hourly), and detailed invoices. The better your documentation, the easier it is to resolve misunderstandings.

Track dependency and plan for gaps

Your bookkeeping can help you plan for client dependency. Keep an eye on cash reserves, average monthly expenses, and how long you could operate without income. A simple monthly summary can show whether you’re building a buffer.

What to include in your bookkeeping records if you bill hourly

If you bill hourly, time records become part of your financial documentation.

Keep timesheets or time tracking exports showing dates, tasks, and hours. Link time entries to invoices where possible. If a client questions a bill, a detailed time log is often the quickest way to resolve it without discounting your work unnecessarily.

What to include if you bill fixed fees or retainers

Fixed fees and retainers can simplify billing, but you still need clear records.

For retainers, keep documentation showing: what the retainer covers, the billing schedule, whether unused hours roll over, and how overages are billed. Record payments in a way that makes it clear which period they cover. If you provide monthly service, label invoices by month and store any usage reports or deliverable summaries that support the value delivered.

How to make records audit-ready without overdoing it

“Audit-ready” sounds intimidating, but it simply means your records tell a coherent story. For each income transaction, you can show the invoice and the payment. For each expense, you can show the receipt and the payment. For each major claim (travel, home office, equipment), you can show the calculation and supporting documents.

You don’t need a complex system to achieve this. You need completeness, consistency, and a habit of filing documents while they’re fresh.

Final checklist: the bookkeeping records you should keep with one or two clients

If you want one final list to follow, focus on these categories:

1) Income documentation: invoices issued, receipts issued, credit notes, payment confirmations, bank deposits, and processor reports.

2) Expense documentation: receipts, vendor bills, subscription invoices, and proofs of payment.

3) Client agreements: contracts, SOWs, proposals, and written scope changes.

4) Tracking tools: an income/expense ledger, accounts receivable list, accounts payable list, and reconciliation notes or reports.

5) Specialized logs: mileage logs, travel documentation, home office support (if used), and an asset register for equipment.

6) Tax records: tax returns, sales tax/VAT filings (if applicable), proof of payments, and year-end summaries.

With one or two clients, your bookkeeping can be clean, fast, and surprisingly powerful. Keep the right records, store them logically, and reconcile regularly. You’ll spend less time chasing paperwork, reduce risk, and gain a clearer view of how your business is performing—even if it’s a very small one.