Straight answers when you need them.
Practical guidance for preparing your accounts, filing your Corporation Tax return and dealing with HMRC or Companies House.
SimpleCompanyTax help articles.
Every public help article, in one place.
How to amend a CT600
Correct a filed return: HMRC amendments and Companies House revised accounts, step by step.
Read guide →UPDATED 16 JULY 2026Audit exemption for micro-entity accounts
Why audit-exemption settings are applied automatically to supported accounts.
Read guide →UPDATED 25 JULY 2026Balancing charges: selling an asset you claimed capital allowances on
Sold an asset you claimed AIA on? Where to enter the balancing charge and profit on disposal.
Read guide →UPDATED 25 JULY 2026Selling a property or investment: chargeable gains on your CT600
Company sold a property or investment? How to compute the gain and file boxes 210-220 with us.
Read guide →UPDATED 25 JULY 2026CT600 filing errors, explained
Understand common HMRC rejection codes, and the checks that stop a bad return before it is sent.
Read guide →UPDATED 17 JULY 2026Disallowable expenses: entertaining, fines and your Corporation Tax
Entertaining and fines stay in your accounts but are added back for tax. Here is how to enter them.
Read guide →UPDATED 25 JULY 2026Dividends in your accounts
Where dividends paid and received appear in your annual accounts.
Read guide →UPDATED 25 JULY 2026Dividends received and your Corporation Tax rate
Dividends received are exempt from tax but can still change which Corporation Tax rate you pay.
Read guide →UPDATED 26 JULY 2026Companies that own property and shares: what we can file
Owns property and listed shares? How each part is taxed, and the FRS 105 rules that apply.
Read guide →UPDATED 26 JUNE 2026Filing to HMRC, Companies House, or both
Choose both filing destinations or send only the outstanding filing.
Read guide →UPDATED 6 JULY 2026Final CT600 when your company has stopped trading
File the last Corporation Tax return and stop HMRC expecting another one.
Read guide →UPDATED 24 JULY 2026Setting up a Government Gateway account to file Corporation Tax
Create a Government Gateway ID, add Corporation Tax, and link your company UTR before you file.
Read guide →UPDATED 22 JULY 2026LLPs: what you file instead of a CT600
Why an LLP files an SA800 rather than a CT600, and why we cannot file for LLPs.
Read guide →UPDATED 26 JUNE 2026Your first year: filing when your accounting period is over 12 months
Why a long first period needs two CT600s and how we handle the split.
Read guide →UPDATED 14 JULY 2026Loss carry-back claims and Corporation Tax refunds
Show an expected refund in your accounts and make the claim with HMRC.
Read guide →UPDATED 29 JUNE 2026Paying your Corporation Tax after you file
When and how to pay HMRC using the correct accounting-period reference.
Read guide →UPDATED 25 JULY 2026PDF copies of your filing documents
View, print, and share PDF copies of everything that was filed, including next year’s carry-forward figures.
Read guide →UPDATED 25 JULY 2026Property income on your CT600: rent, expenses and property losses
File rent from UK property: the box 190 net figure, property losses, and what is out of scope.
Read guide →UPDATED 25 JULY 2026Which company types SimpleCompanyTax supports
We file for UK private limited companies that are micro-entities. See what is in and out of scope.
Read guide →UPDATED 28 JUNE 2026Using trading losses to reduce your Corporation Tax
Use an earlier trading loss against this year’s trading profit.
Read guide →Still need help?
Contact our UK support team or start a filing and save your progress as you go.