CT600 Fields TinyTax Does Not Include (Exporter, Bank Details, Expenses)

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id: ct600-fields-not-asked title: CT600 Fields TinyTax Does Not Include category: ct600-filing tags: [exporter information, bank details, repayment, expense breakdown, directors salary, advertising costs, file upload, attachment, CT600 optional fields, amendments included, amendment fee, box 95, CT600A, staff costs, pension, other charges, expense categories] applies_to: [trading, dormant, all] difficulty: beginner last_updated: 2026-03-16 related: [ct600-amendments, filing-your-first-ct600, common-expense-categories]

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TinyTax asks for the figures HMRC actually requires to calculate and submit your CT600. There are some fields on the full CT600 form that TinyTax does not ask for -- this guide explains which ones and why that is fine.

Exporter Information

The CT600 has an optional section asking whether your company exports goods, services, or both. TinyTax does not include this field.

HMRC treats this as supplementary information. It does not affect your tax calculation, and leaving it blank does not prevent your CT600 from being accepted. Your submission will be processed exactly the same whether or not this is populated.

Bank Details for HMRC Repayments

TinyTax does not ask for bank account details for HMRC repayments.

The CT600 form itself is not the mechanism HMRC uses to make repayments. If HMRC owes you money (for example, because you paid tax early and are due a refund of interest), you can register your bank details directly in your HMRC Corporation Tax online account, or HMRC will issue a cheque if no details are held. This is handled separately from the CT600 submission.

Expense Breakdown

TinyTax asks for total trading expenses grouped into four categories: cost of raw materials and consumables, staff costs, depreciation, and other charges. HMRC does not require a sub-breakdown within each category -- for example, you do not need to separate director's salary from pension contributions within staff costs, or list individual items within other charges.

The iXBRL accounts and tax computations that TinyTax generates include these same category totals, tagged with the appropriate iXBRL identifiers for HMRC's system. For micro-entity and small company accounts, this is the level of detail HMRC requires -- there is no need to enter a further breakdown, and no facility in TinyTax to do so.

If you are unsure how to split your expenses across the four categories, see our guide on common expense categories.

File Uploads and Free-Text Fields

TinyTax does not support attaching additional documents to a CT600 or accounts submission, and there is no free-text field for supplementary information.

HMRC's electronic filing protocol only accepts the CT600 XML along with the iXBRL accounts and computations. There is no facility in the HMRC gateway for additional file attachments. If you need to communicate something specific to HMRC (for example, to explain an unusual entry), you would need to contact HMRC separately after filing.

Do Amendments Cost Extra?

No. Amendments are included in your subscription at no extra cost. If you need to correct and resubmit your CT600 after it has been accepted, you can do so from your dashboard at any time within the statutory 12-month amendment window.

See our guide on filing an amended CT600 for step-by-step instructions.

Common Questions

Will HMRC reject my CT600 because these fields are blank?

No. The fields described above are either optional in HMRC's schema or handled through separate channels. TinyTax has submitted thousands of CT600s without these fields and they are accepted without issue.

What about Box 95 and CT600A?

Box 95 asks whether you need to complete form CT600A (the close company loans to participators form). If your director's loan account was overdrawn at any point during the year but was fully repaid by the end of the accounting period, no S455 tax is due, Box 95 is not ticked, and no CT600A is needed. You file your CT600 normally through TinyTax.