How should small businesses organise their accounting and tax records?

Accounting and tax records should be prepared regularly rather than left until the end of a reporting period. For small businesses, systematic record-keeping considerably reduces the time needed to prepare returns or respond to enquiries.

Many new businesses focus only on invoices, but tax records often need a complete paper trail: contracts, acceptance records, proof of payment, invoices, internal records and evidence that the goods or services were actually supplied. When these documents are scattered, missing or inconsistent, accountants may struggle to establish whether expenses are properly supported, leaving the business to spend more time explaining them.

Under the applicable rules on accounting, tax administration, invoices and supporting documents, businesses must prepare, retain and produce accounting and tax records when requested by a competent authority. Preparing documentation should therefore be an operating habit from the moment goods are purchased or sold, salaries paid or contracts signed, rather than merely an accountant's month-end task.

Each set of records should explain the transaction

For each purchase or sale, businesses should retain a set of documents explaining three basic points: why the transaction took place, how its value was determined and how payment was made.

Typical records include a quotation or purchase request, a contract or purchase order, any amendments or addenda, delivery or acceptance records, electronic invoices, proof of payment and important correspondence. Transactions involving goods may also require stock issue notes, goods receipt notes, waybills or delivery documents. For services, the scope of work, deliverables and acceptance records are often more important.

Small businesses do not necessarily need overly complex documentation, but should avoid retaining only an invoice without evidence of the need for, substance and outcome of the transaction. An invoice in the prescribed form is not enough to establish the full economic substance of an expense if the supporting records are unclear.

Classify records by business function

For easier management, businesses should divide their records into the following main categories:

• Sales: contracts, quotations, purchase orders, acceptance records, sales invoices and receipts.
• Purchasing: purchase requests, contracts, purchase invoices, payment evidence and delivery documents.
• Personnel: employment contracts, payroll, timesheets, salary and bonus decisions, and insurance records where applicable.
• Banking and cash: bank statements, credit and debit advices, receipts, payment vouchers and internal approvals.
• Assets and equipment: procurement, handover, allocation, inventory and disposal records where applicable.

This classification helps business owners and accountants retrieve documents quickly for checks, reports or tax authority requests. Where accounting is outsourced, classifying records in advance also reduces errors when transferring documents.

Electronic storage still needs clear rules

Electronic invoices and digital records save small businesses considerable time, but are effective only when file naming and access controls are clear. Businesses should adopt a consistent folder structure by year, month and transaction category. File names should include the date, counterparty, transaction description and amount or invoice number to make retrieval easier.

For example, a purchase invoice could be named: 2026-07-03_Nha-cung-cap_Dich-vu-marketing_HD000123.pdf. Naming conventions need not be elaborate, but must be consistent. Avoid generic names such as scan.pdf, hoa-don-moi.pdf , or distributing files across multiple channels without bringing them into a central repository.

Businesses should also schedule weekly or monthly document transfers to their accountant rather than waiting until the filing deadline. Early review allows common errors, such as an incorrect company name or tax identification number, missing payment evidence or missing acceptance records, to be resolved sooner.

Common small-business mistakes

Common mistakes include accepting invoices without checking the buyer's details, paying from personal accounts without adequate explanation, lacking contracts or acceptance records for high-value services, failing to retain payroll and attendance records, or leaving documents in employees' personal email accounts without backing them up to the shared system.

Another risk is preparing records only when an explanation is requested. This often leaves gaps and makes it difficult to reconstruct transaction dates without relying on someone's memory. Records should be organised consistently from the first day of operations, particularly for recurring monthly expenses such as office rent, software, marketing, transport, salaries and allowances.

Start with a simple checklist

Small businesses can begin with a short checklist for each transaction type. Before payment, check that a contract or request is available, all invoices have been received, invoice details are correct, delivery or acceptance records are complete and files are saved in the correct folder. For unusual expenses, consult the accountant or adviser before proceeding to avoid having to resolve problems later.

This article provides general information only. Depending on the industry, scale, tax filing method and actual records, businesses should consult their accountant or a legal and tax adviser before applying it.