A few years ago, a return that left out a small side income could go unnoticed. Today, tax authorities everywhere use data to compare what taxpayers declare with what others report about them: employers, banks, suppliers, land registries, import records and electronic invoicing systems. This does not mean that everyone is being watched in detail. It means that inconsistencies are easier to spot, and honest, consistent records matter more than ever. This guide explains the idea in general terms. How KRA applies it in practice can change.

What data matching is

Data matching means comparing information from several sources to find differences. If your employer reports a salary and you declare less, the two figures do not match. If a supplier reports a sale to you that you do not show as a purchase, or a business reports sales that exceed its declared turnover, there is a gap. A system flags the difference, and an officer may ask for an explanation.

Where the data comes from

Information can come from many places: employers' PAYE returns, VAT returns and electronic invoices, withholding tax certificates, imports and exports records, bank reporting, land transactions, licensing records and tax returns of other taxpayers. Electronic invoicing in particular makes sales and purchases visible; see eTIMS e-invoicing explained and bookkeeping in the eTIMS era.

Common mismatches

  • Employment income on a P9 that differs from the amount in the return.
  • Rental income reported by a tenant or agent that is not in the landlord's return; see withholding tax on rent for tenants and agents.
  • Sales on electronic invoices exceeding sales in a VAT or turnover tax return.
  • Purchases claimed that suppliers did not report.
  • Imports at a value that does not match declared costs or sales.
  • Withholding tax credits claimed without matching certificates.
  • Wrong PINs on documents, so credit lands in the wrong account.

Why consistency is your best defence

If your returns agree with your records and your records agree with what others report, a match raises no questions. Most mismatches are innocent: a wrong PIN, a timing difference, a typing error. But they can still produce notices and penalties. The fix is to find and correct them before KRA asks. Use how to check and correct your iTax profile and how to read your iTax ledger and statement of account to see what KRA's records show about you.

Reconcile before you file

Before you submit a return, compare your figures with the documents others hold. For employees, check the P9 against payslips; see understanding your P9 form, box by box. For businesses, compare your sales records with the invoices you issued and your purchases with the invoices you received; the VAT return working sheet and the VAT input invoice register help. Landlords should check that their rent records agree with tenants' payment records and certificates.

Respond properly to a query

If KRA writes to ask about a difference, read the letter carefully, find the cause and answer in writing with evidence. How to read a KRA assessment letter line by line explains how to analyse a notice. If the mismatch was a mistake, correct the return and pay any tax due. If KRA is wrong, explain with documents. Do not ignore the letter.

Keep a record of the explanation

When you find an unusual item, note why it happened. A short explanation kept with the records saves time later if the question is asked again. Keep records for the required period; see keeping tax records for five years: digital vs paper.

Avoid shortcuts

Under-declaring income, claiming expenses you did not incur or ignoring invoices will be harder to hide as data sharing grows. The consequences include penalties and interest; see the difference between tax avoidance and tax evasion and the KRA penalty calculator. Honesty is now also the easiest strategy.

Make it routine

Reconcile monthly for a business and annually for an employee. Keep your documents tidy, make sure PINs are right on everything you issue and receive, and file on time. Data matching rewards the taxpayer who keeps good records, and catches those who do not.

A practical example

A landlord receives rent through an agent who deducts withholding tax and reports it. If the landlord leaves that rent out of the annual return, the agent's report and the return do not match. A letter follows, with tax, interest and a penalty. Had the landlord compared the agent's certificates with the rent records before filing, the mismatch would have been found at once. The habit of reconciling before you file is worth far more than a defence afterwards.