Questions & Answers

Yes. You prepare your accounts once and Tax Optimiser uses the same figures to produce the iXBRL-tagged accounts, the tax computation and the CT600. The accounts are filed with Companies House, and the CT600, accounts and computation are submitted to HMRC, all directly from the app. Find out more about CT600 filing.

Micro-entity accounts under FRS 105, small company accounts under FRS 102 Section 1A, and dormant company accounts. Tax Optimiser guides you to the right standard when you set up the company.

Yes. You can connect Xero, QuickBooks or Sage to pull in your trial balance, or import a trial balance from a spreadsheet exported from any other bookkeeping software.

A Corporation Tax accounting period can never be longer than 12 months, so a longer period of accounts needs two CT600 returns: one for the first 12 months and one for the remainder. You prepare one set of accounts and Tax Optimiser splits the profits and produces both returns for you.

Sole traders and landlords must use Making Tax Digital for Income Tax from 6 April 2026 if their qualifying income from self-employment and property is over £50,000, from 6 April 2027 if it is over £30,000, and from 6 April 2028 if it is over £20,000. Qualifying income is based on the tax return for the tax year two years earlier.

No. The MTD for Self Assessment and VAT modules run independently of each other. You can use either module separately based on your needs.

Yes. You can carry on using your existing Excel spreadsheet as long as you calculate the 9-box VAT totals. Then you will need to specify in Tax Optimiser the sheet and cells to extract the data from. Finally, use our upload section to bridge the Excel file to send to HMRC.

Yes. We support Excel 97 onwards. We have also had clients successfully use our software with a range of other spreadsheet software. If you have any doubt, feel free to sign up and try it out.

Yes. As long as you are able to export an Excel/CSV file from your existing system or software, you can upload it to Tax Optimiser to extract the data and submit it to HMRC. All you need to do in the VAT settings is set what sheet and cells to extract the data from. We have had clients successfully use our software on a range of software including all versions of Sage Line 100, Sage Instant, Sage 50, Sage 200 and Access Dimensions.

No. As part of the new legislation, you cannot just manually add up the totals and key them into the spreadsheet. All the values need to be calculated either from software or formulas within the spreadsheet.

You will just need to output an Excel/CSV file with the 9-box totals calculated. You can then upload your Excel spreadsheet into our software to send it to HMRC.

Yes. There is the ability to add your own logos, brand colours and your own web address, e.g. https://mtd.acmeaccountants.com.

Yes. The Government Gateway user ID and password you enter for filing Corporation Tax returns are encrypted before they are saved, and our database is also encrypted at rest. Once saved, your password is never displayed again — not to you, your team, or our staff — and is only decrypted at the moment we send your return to HMRC. To change it, simply enter a new one.

For VAT and Making Tax Digital for Income Tax we connect using HMRC's own sign-in, so we never see your HMRC password for those at all.