How to File Contracts, Invoices and Bank Statements
Author: Junanda ConsultingReviewed by: Junanda Service Team2026-09-19
Contracts, invoices and bank statements are the three most basic categories of source material a company holds. Day to day they sit with different people in different places, and it is usually only when a tax verification, an audit, a financing due diligence or a lawsuit arrives that gaps and mismatches become visible. Filing is not about putting paper in a cupboard; it is about building a structure in which the three corroborate one another, so that when something is needed it can be produced within three minutes and it reconciles. This article sets out a filing method you can apply directly.
How Contracts, Invoices and Bank Statements Relate
Understanding what each of the three proves explains why they should be filed together:
Contract: proves rights and obligations. It sets out what is being transacted, the amount, the settlement method, delivery and acceptance conditions, and liability for breach.
Invoice: proves the tax position. It determines the basis for recognising revenue or cost, and for input credit and pre-tax deduction.
Bank statement: proves the movement of funds. It shows whether payment was actually made and received, and whether the amount and timing are consistent with the contract and the invoice.
The ideal state is that the amount and settlement method agreed in the contract are corroborated by the invoice and the bank statement, and that any differences have a reasonable explanation (instalment receipts, advance payments, retention money, discounts). Tax verification and audit focus on precisely this chain: a break anywhere in it carries an explanation cost.
Designing the Filing Hierarchy and Naming Files
A three-level structure is recommended — time first, then counterparty, then document type — because it is the easiest to search.
Level one: financial year. Create folders by accounting year. For transactions straddling a year end, file by the year in which the business occurred and index them in both years.
Level two: by counterparty or project. Create sub-directories per customer, supplier or project. Where the same customer is both buyer and supplier, keep "sales" and "purchases" as separate branches.
Level three: by document type. Within each counterparty directory, use a fixed set of categories: contracts, invoices, bank statements and receipts, logistics or acceptance documents, and other (statements of account, correspondence).
A single naming convention is the most effective step for improving retrieval. The recommended format is year-month_document type_counterparty abbreviation_amount_sequence, for example:
Example file name
Notes
2026-03_Sales invoice_Customer A_125000.pdf
Sales invoice, with year-month and amount
2026-03_Purchase contract_Supplier A_380000.pdf
Purchase contract
2026-03_Bank receipt_Customer A_125000.pdf
Receipt of payment
2026-03_Statement of account_Supplier A_monthly.xlsx
Monthly reconciliation
Once settled, the naming rule has to be applied across the whole company and written into the filing policy. Otherwise, six months later different people will name files differently and retrieval will still depend on scrolling.
The resulting structure looks like this:
Level
Directory
Contents
Naming example
Level one
Financial year 2026
Sub-directories for each counterparty
2026
Level two
Customer A
Sales branch sub-directory
2026_Customer A
Level three
01 Contracts
Sales contracts and supplementary agreements
2026-03_Sales contract_Customer A_500000.pdf
Level three
02 Invoices
Output invoices and schedules
2026-03_Sales invoice_Customer A_125000.pdf
Level three
03 Bank
Receipts and statements
2026-03_Bank receipt_Customer A_125000.pdf
Level three
04 Delivery
Release notes, signed receipts
2026-03_Signed receipt_Customer A.pdf
Level three
05 Other
Statements of account, correspondence
2026-03_Statement of account_Customer A.xlsx
Key Points for Electronic Filing
Scan clarity: key documents such as invoices and bank receipts should be scanned at a resolution at which the amount, date and number are legible, avoiding angled phone photographs. For invoices, keep the original electronic file as well (for example the original PDF), rather than only a screenshot.
Originals: electronic copies are a means of retrieval and backup. Paper originals, or original electronic invoices, still have to be kept as required, and the two cannot substitute for each other.
Cloud drive permissions: allocate access by role — finance can write, business can read, external parties have no access. Directories containing customer information should be restricted.
Backup: keep at least two copies, one local and one in the cloud, and verify periodically that the backup works. Backup is not "it was saved"; it is "it can be restored".
Version control: when a file is modified, save a new version with the date marked, so the original can still be traced.
Binding and Storing Paper Originals
Paper vouchers should still be bound in line with the accounting archives standard:
Arrange by month and in voucher number order, with attachments immediately following the voucher they belong to.
Suggested attachment order: invoice, then contract or order, then goods receipt or acceptance note, then bank receipt, then other explanations.
Check attachments for completeness before binding. Where one is missing, note it on the voucher and have the handler sign.
Add a cover showing the period, the volume number and the first and last voucher numbers, for ease of later retrieval.
Store in a dry, fire-resistant, lockable cabinet, and keep a register recording the number of volumes and where each is stored.
Obtaining and Filing Bank Statements
Download monthly: export the statement and receipts from online banking at a fixed time each month. Do not wait and catch up at year end, because cross-period exports are more likely to be incomplete or inconsistent in format.
Reconcile with the books: check the statement line by line against the bank deposit ledger, and confirm that receipts and payments of revenue, cost, expenses and taxes have all been recorded.
Register outstanding reconciling items: for items the bank has recorded but the company has not, or the company has recorded but the bank has not, prepare a bank reconciliation statement and keep a register of outstanding reconciling items, following each one monthly until it is cleared.
File by account: where a company has several accounts, distinguish the basic account, general accounts and foreign currency accounts and file them separately rather than mixing them into something impossible to reconcile.
Personal accounts and petty cash: company business should in principle be settled through the company account. Where petty cash or temporary advances genuinely exist, keep the approval and clearing records.
Retention Periods, Retrieval and Handover
Accounting archives and tax-related materials have statutory retention periods, and these differ by category (some retention periods for tax-related materials have been adjusted in the past; the latest rules apply). The prudent approach is to retain material for the longest period required by law, and before destruction at the end of the period to prepare a destruction list and obtain internal approval. Individuals must not dispose of material at their own discretion.
For retrieval and handover, two simple registers are recommended. The first is an internal borrowing log, recording the borrower, the material, and the dates it was taken out and returned. The second is a handover list, used when the finance person or the bookkeeping agency changes: check and sign off item by item against the index, confirming the number of volumes, the scope of electronic material and how passwords are handed over. These two registers play a critical role if a dispute arises.
Self-Check Checklist
Contracts, invoices and statements can be matched to individual transactions, with differences explained in writing
The filing structure is unified as three levels: year, counterparty, type
The file naming convention is documented and applied by everyone
Electronic copies are legible, original electronic invoice files are kept, and screenshots are not used instead
Cloud drive permissions are allocated by role, with key directories restricted
Both local and cloud backups are in place, and restoration has been tested
Paper vouchers are bound monthly with a consistent attachment order and an archive register
Bank statements are downloaded and reconciled monthly, with a register of outstanding reconciling items tracked each month
Both a borrowing log and a handover list are in place and actually used
Destruction of expired archives has a list and internal approval, and is never handled by an individual
Common Pitfalls
Keeping only invoices, without contracts and bank receipts, so that differences in amount or timing cannot be explained.
Leaving material scattered across messaging apps, email and personal computers, so that it is lost when the person leaves.
Saving electronic invoices only as screenshots or printouts, without the original electronic file, which affects later verification.
Downloading statements in one go at year end, so that cross-period data is incomplete and reconciliation becomes harder rather than easier.
Assuming the bookkeeping agency will hold all the originals, without keeping your own register, so that nothing can be checked off at handover.
This article is general business information prepared by Junanda Consulting. Specific policy positions, tax rates, deadlines and procedural requirements are subject to the latest official versions issued by the competent authorities. To understand how these requirements apply to your business, please contact Junanda Consulting for further information and support.
