Tolvi Corporation Tax, corporation tax software for accountantsA CT600 you can trace back to its computation and source
Tolvi Corporation Tax is corporation tax software for accountants. It produces draft Company Tax Returns for UK limited companies and charities, for accounting periods starting on or after 1 April 2023: the CT600 with the CT600A, C, E, J, L and M, the computation and the tagged accounts, ready for you to review and your partner to approve.


Its place in the chain of figures
From the figures to a partner’s approval
Step 1: Start the return
From a Working Papers file, an accounts set or typed figures.
Step 2: Check the computation
Rates, marginal relief, capital allowances, losses and common adjustments, with the boxes filled from them.
Step 3: Review
Send it for review, and raise and clear review points on the return.
Step 4: Approve
A partner approves by default, and you record the client’s confirmation.
Step 5: Download
The CT600, the computation, and the iXBRL accounts and computation.
What it does
A return you can follow back to its source
Three ways in
A Working Papers file, a Tolvi Accounts set or typed figures.
The computation behind the boxes
Tax is worked out to the penny from whole-pound profits, using the banded rates and marginal relief that apply from 1 April 2023.
CT600A for loans to participators
Loans to participators, repayments and relief go on the CT600A, and roll forward reduces older loans oldest first.
CT600L for R&D claims
The merged scheme and enhanced R&D intensive support steps, worked through in order, with what’s left carried and rolled forward. Returns with an R&D claim can’t currently be filed from Tolvi, and one position, box L65 where a credit was brought forward, is blocked until HMRC says how its online rules and the law fit together.
CT600C and group relief between your clients
Claims, surrenders and notices of consent between clients in your firm. The 75% test is the facts a person gives, and a withdrawn notice is replaced, never changed. Linked clients suggest related companies and an associated company count, and nothing moves until someone presses Use.
CT600E, J and M
The CT600E for charities and community amateur sports clubs, where exemption is what a person says and a charity’s accounts can suggest the figures.
Amendments
An amendment is a new draft with its own review, approval and client’s confirmation, so the original is never changed. A partner can record that a return went in through other software: that’s their record, not HMRC’s word.
Review and approval on the return
Draft, in review, approved. A partner approves by default, and a firm can allow managers. An AI assistant can never approve or file.
Also: It names what’s out of scope · Everything to download. Every feature
With the rest of Tolvi
Tolvi Working Papers
Section T carries over
What Tolvi Working Papers doesTolvi Accounts
The accounts come too
What Tolvi Accounts does
Tolvi Corporation Tax: Free during the beta.
Compare every productWhere it stops today
What’s live and what’s comingFiling with HMRC from Tolvi Coming
Filing Company Tax Returns from Tolvi is coming. It isn’t open today, so you file through your existing tax software.
- Limited companies and charities only: not LLPs, and a charitable trust’s return is an SA900.
- There’s no group computation. Tolvi blocks filing where there’s consortium relief, overseas group relief, an overseas branch, Northern Ireland trading, or a supplement other than the CT600A, C, E, J, L and M.
- Treaty relief, underlying tax and some R&D positions, such as a claim under both schemes or surrendering a credit to a group, aren’t supported, and they block filing.
- Accounting periods starting before 1 April 2023 are refused, because their results can’t be checked against HMRC’s published test.
- CT600M rows and CT600E assets and legacies go through the API for now, not the screen.
- None of this has yet been through HMRC’s test service, or been reviewed by an outside accountant.
Questions about Tolvi Corporation Tax
What does Tolvi Corporation Tax cover?
Company Tax Returns for UK limited companies and charities, for accounting periods starting on or after 1 April 2023, with the CT600, the CT600A, C, E, J, L and M, amendments and the computation. Consortium relief, overseas branches and other supplements are named on the return and blocked from filing.
Does it handle groups?
It handles group relief between clients in your firm: claims, surrenders and notices of consent on the CT600C. The 75% test is the facts a person gives, and there’s no group computation, so a person works out what each company can claim. Consortium relief and overseas group relief aren’t supported.
Can we amend a return?
Yes, as a new draft with its own review, approval and client’s confirmation. A partner can record that the original went in through your existing tax software.
Do we need Working Papers or Tolvi Accounts to use it?
No. Corporation Tax works from a Working Papers file, a Tolvi Accounts set or figures you type, and needs neither product.
More answers on the questions and answers page.