Post-filing control

CT600 payment reconciliation workflow for accountants.

Filing the Company Tax Return does not prove the Corporation Tax bill was paid, allocated, nil, refunded, or reconciled. Practices need a post-filing workflow that keeps payment evidence with the CT600 file.

Why payment reconciliation belongs in the CT600 workflow

The CT600 and computation show the tax due, repayable, or nil. HMRC payment guidance then determines the correct reference, payment method, clearing time, nil-to-pay route, and account-check process.

If the practice stops at submission, the client file may answer "was it filed?" but not "was the right amount matched to the right period?" That is the question clients ask when reminders, interest, or refunds appear later.

The post-filing record to keep

A useful practice file should capture:

  • Final CT600 result: tax due, repayment, or nil-to-pay position.
  • Accounting period covered by the return.
  • Payment deadline and the evidence available for the period.
  • Correct Corporation Tax payment reference for that accounting period.
  • Payment method, expected clearing time, and person responsible for payment.
  • Evidence of payment, HMRC account check, nil-to-pay notification, repayment claim, or refund follow-up.
  • Client communication showing what the practice did and what the client must do next.

The period-specific reference trap

GOV.UK says the Corporation Tax payment reference changes with each accounting period. If a director pays from a saved bank payee, the old reference can remain in the banking template.

The company may have paid HMRC, but the money can be harder to match to the right period. Practices should make the current-period reference clear in the client pack while avoiding public disclosure of private identifiers.

Nil and repayment cases still need follow-up

A company must still file a Company Tax Return when there is no Corporation Tax to pay. HMRC also provides a way to tell HMRC no payment is due. If the return is nil or repayable, the file should explain why and record any required follow-up.

Repayments and early-payment interest need the same discipline. The file should show what the client expects, what HMRC confirms, and whether any mismatch needs action.

Interest and late payment risk

HMRC may charge interest when Corporation Tax is paid late and may pay interest when tax is paid early. The practice file should separate the filed tax position from the payment evidence and the HMRC account position.

The practical control is to keep filing date, payment due date, payment evidence, HMRC account check, and client follow-up together. That gives the practice a cleaner answer when a client forwards an HMRC reminder.

How Robocount supports post-filing control

Robocount connects CT600 preparation, review, submission readiness, and evidence. Payment reconciliation is part of that same lifecycle: the filed return should lead to a clear payment, nil, refund, or follow-up action.

  • Keeps the final tax position visible alongside the CT600 filing workflow.
  • Helps practices explain payment and nil-to-pay next steps after filing.
  • Supports cleaner audit trails for HMRC responses, amendments, and client follow-up.
  • Links naturally to client approval, submission evidence, rejected returns, and amendments.

FAQ

Does filing a CT600 pay the Corporation Tax automatically?

No. Filing and payment are separate workflows. The company still needs to pay using an accepted method unless the tax position is nil, repayable, or otherwise settled.

Can a company pay Corporation Tax by post?

GOV.UK says Corporation Tax cannot be paid by post. Companies should choose a payment method that allows enough time for the payment to clear.

What if there is no Corporation Tax to pay?

The company must still file the Company Tax Return. HMRC also provides a nil-to-pay notification route to stop unnecessary payment reminders.

How can a practice check whether HMRC received payment?

GOV.UK says companies can check their HMRC online account, which should update within a few days of HMRC receiving payment. Practices should record the evidence available to them and any client confirmation needed.

Useful official references

This guide is general product and filing workflow information, not tax advice. Check current HMRC guidance and the company's facts before filing or paying.