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Corporation Tax

CT600 periods, credentials, amendments, and what to expect after submit.

• CT600 filing checklist

  What to gather before you open the Corporation Tax rail — periods, P&L, balance sheet, and prior filings.

• What happens after you submit a CT600

  Acceptance receipts, audit entries, and how to prove the filing later.

• Previous period required — unblock the current CT600

  Why Hydra (and HMRC) insist on earlier periods first, and how to clear the blockage.