How to Build a Monthly VAT Reconciliation Process for Tax, Invoices and Returns

You may already be issuing VAT invoices in Sri Lanka, yet every month the sales ledger, purchase documents, accounting records and VAT return figures still fail to match. The later these gaps are identified, the more time and effort may be needed to retrieve documents, correct records and explain discrepancies.

The purpose of monthly reconciliation is not to produce a number just before the filing deadline. It is to ensure that every transaction included in the VAT calculation can be traced back to the relevant contract, invoice, payment or receipt record, and accounting treatment. What you need is a consistent monthly routine, not a last-minute document search.

Correct a common misunderstanding first

Many businesses assume that VAT returns are mainly the accountant’s responsibility and that operational teams only need to hand over invoices. In practice, the reliability of a VAT return depends on whether information moves completely and accurately between sales, procurement, finance, operations and the appointed external professional firm.

For example, a sales team may have quoted a customer and received payment, but no invoice has yet been issued. A procurement team may have received a supplier bill without confirming whether the document meets the company’s record-keeping requirements. Finance may have booked an expense without obtaining the documents needed to support the related tax treatment. If these issues are left until the return is being prepared, they can lead to missing invoices, duplicate entries, incorrect tax direction or transactions being recorded in the wrong period.

Split the monthly review into four working papers

Do not rely on one summary spreadsheet alone. A more robust approach is to maintain four traceable sets of working papers based on the source of each transaction, with each set capable of being reconciled against the others.

1. Sales and output VAT working paper

This working paper should answer a basic question: which transactions during the period should be included in the sales records, have invoices been issued, and have the invoice values and VAT amounts been recorded correctly?

For each transaction, consider recording at least:

• Customer name and customer identification details;
• Contract, purchase order, quotation or service confirmation reference;
• Invoice number, invoice date and transaction description;
• Amount excluding VAT, VAT amount and amount including VAT;
• Payment status and the related bank entry or receipt evidence;
• Any corrections, cancellations, credit notes or period-end adjustments.

A sales ledger should not depend only on invoices already issued. You should also compare the invoice list against operational information for the month, such as contract performance, deliveries, completed services, advance payments and customer refunds. This helps identify transactions missed because business and finance information were not properly connected.

2. Purchase and input VAT working paper

The key question for purchase records is not simply whether a supplier invoice exists. You need to establish whether the commercial substance of the purchase, the supporting documents and the accounting treatment are consistent with one another.

Each purchase may be linked to the following documents:

• Supplier invoice and supplier details;
• Purchase order, contract, goods received note, delivery note or evidence of completed services;
• Payment request, payment proof and bank records;
• Relevant department, project or cost centre;
• Customs, tax and freight documents for import transactions;
• Any personal payments, related-party transactions, advance payments or subsequent refunds.

The document trail for imported goods is often longer. If you appoint a customs broker to handle imports, you may also refer to the published article, After Appointing a Customs Broker for Imports: How to Reconcile Declarations, Tax Payments and Cargo Release Status. Import declarations, tax records, cargo release documents and inventory or project usage records can then be included in the same monthly review process.

3. General ledger and VAT register reconciliation

Once the sales and purchase working papers are complete, reconcile them line by line against the accounting system records for revenue, costs, payables, receivables, bank accounts and tax-related accounts.

Three types of discrepancies are especially common:

Type of discrepancy	Common cause	Questions to investigate
Invoice appears in the working paper but not in the accounts	Document not posted, incorrect account code, wrong-period treatment	Has the invoice been provided to the bookkeeping team? Which period should it be recorded in?
Amount appears in the accounts but not in the invoice working paper	Missing supporting attachment, manual journal entry, accrued expense	Which commercial document supports this entry? Does additional evidence need to be obtained?
VAT register does not match the general ledger	Tax code setup, data-entry error, inconsistent treatment of credit notes	Does the difference arise from the amount, VAT figure or transaction period?

For discrepancies that cannot be resolved in the same month, maintain an open-items log. Record the responsible person, missing documents, expected resolution approach and whether the matter may affect the current return. Do not leave unresolved issues only in email threads. By the following month, it is often unclear why they were not addressed.

4. VAT return working paper and management confirmation

A VAT return should not be a document prepared by an external professional firm in isolation. Internally, you should retain at least one return working paper showing the source of each return field, the aggregation logic and any material adjustments.

Before submission, the person responsible for business operations or finance may confirm the following:

• Whether the sales listing covers all known business activities for the period;
• Whether purchases and expenses are supported by original documents;
• Whether there are transactions where invoices have not been issued, supplier invoices have not been received, or acceptance has not been completed;
• Whether credit notes, refunds, bad debts, advance payments, related-party balances or one-off high-value transactions require separate explanation;
• Whether the reported figures show unusual movements compared with the prior period, and whether those movements can be explained.

This does not mean that business managers should replace professional tax judgement. It means confirming that the underlying business facts used for the return have not been omitted. The applicable VAT treatment, return format and filing requirements should be confirmed by the appropriately qualified tax professional firm you appoint, based on your company’s circumstances.

A workable monthly timetable

The biggest risk in VAT reconciliation is waiting until two days before the filing deadline. You can set fixed checkpoints around your internal month-end close:

1. Around month-end, business, sales and procurement teams submit their transaction lists together with new contracts, orders and acceptance documents.
2. Finance compiles issued sales invoices, received purchase documents, payment and receipt records, and updates the VAT register.
3. Reconcile the VAT register against the general ledger, bank statements, receivables and payables schedules, then prepare a discrepancy list.
4. Obtain additional documents for unusual transactions or confirm the factual background with the relevant business owner.
5. Provide the completed working papers to the appointed tax professional firm for review and confirm whether the information needed to prepare the return is complete.
6. After filing, archive the filed version, submission acknowledgement, payment records and month-end working papers. Carry unresolved items forward for follow-up in the next month.

If you use an invoicing system, its exported sales listing should be capable of being reconciled against the accounting ledger, customer receivables and invoice-number sequence. A system can reduce duplicate data entry, but it cannot automatically determine whether a transaction has been omitted from a return, whether documents are complete, or whether the business description matches the contract. For checks to make before selecting a system, refer to How Sri Lankan Companies Can Check VAT Invoice and Record-Keeping Requirements Before Choosing an Invoicing System.

Warning signs worth reviewing before filing

The following situations do not necessarily mean that a VAT return is incorrect. They should, however, be investigated before submission:

• Sales increase or decrease significantly, but bank receipts, orders or delivery records do not show a corresponding change;
• Purchase amounts are high for the period, but contracts, acceptance records or payment support are missing;
• Invoice numbers contain unexplained gaps, duplicates or cancellations;
• The same transaction appears in more than one schedule or accounting account;
• Significant amounts are posted to “other”, “miscellaneous” or temporary accounts;
• Import documents, supplier invoices and inventory receipt records cannot be matched;
• The external professional firm repeatedly requests the same category of documents.

The value of these warning signs is that they help you identify process gaps early, rather than searching for an explanation only after a discrepancy has surfaced.

File records for review, not just storage

Organise electronic records by “filing period – transaction type – transaction reference” so that any figure reported in a VAT return can be traced back to the original documents. Contracts, invoices, payment evidence, receipt records, import documents, credit notes, accounting vouchers and VAT return working papers should remain linked to one another.

Where documents are held by different departments, appointing an internal coordinator is important. This person does not replace the accountant or tax adviser in making professional judgements. Their role is to ensure documents are received on time, track discrepancies, maintain version control and clarify responsibilities. MMD Business Support can assist with organising document checklists and coordinating communication between local resources and appointed professional firms; company tax filings and professional opinions should be handled by professional firms with the qualifications required by law.

This content is provided for general information only and does not constitute legal, tax or immigration advice. Specific requirements should be confirmed with the latest guidance from the relevant Sri Lankan authorities and the appointed licensed professional firm.