CT600 Box-by-Box Guide: Every Core Box Explained (2025/26)

CT600 Box-by-Box Guide: Every Core Box Explained (2025/26)

The CT600 form has hundreds of boxes. Most guides skip straight to "the important ones" and leave you wondering what all the others are for. This guide covers every core box on the main CT600 — the company information section, the income and deductions pages, the tax calculation, the credits and payments section, capital allowances, and losses — so you know exactly what each one does and whether you need to fill it in.

If you're filing for a straightforward small company, you'll probably use about 15–20 of these boxes. Our DIY CT600 filing guide walks through the full process step by step. But knowing what the rest are for means you won't accidentally skip one that applies to you.

Before You Start: What You Need

Have these ready:

• Your company's accounts for the period (profit & loss and balance sheet)
• UTR (Unique Taxpayer Reference) and Company Registration Number
• Your accounting period start and end dates (check your CT600 filing deadline too)
• Details of any capital allowances, losses, or special claims

Company Information (Boxes 1–8)

These boxes identify your company and appear at the very start of the form. Most are pre-populated if you're filing via software.

Box 1 — Company name

Your company's official name exactly as registered at Companies House. Don't abbreviate it unless you've agreed an abbreviation with HMRC.

Box 2 — Company registration number

Your 8-digit Companies House number. Find it on your certificate of incorporation or any letter from Companies House. Scottish companies start with SC, Northern Irish with NI — those letters are part of your number.

Box 3 — Tax reference (UTR)

Your 10-digit Unique Taxpayer Reference from HMRC. It's on any Corporation Tax letter — specifically the last 10 digits of the 13-digit number at the top. If you can't find it, you can request it online or call HMRC on 0300 200 3410.

Box 4 — Type of company

A code for your company type. Enter 0 if you're a normal UK limited company — which covers the vast majority of small businesses. Special codes apply for unit trusts (1), close investment-holding companies (2), companies in their second or later year of liquidation (3), qualifying asset holding companies (4), insurance companies (5), members' clubs (6), property management companies (7), charities (8), and REITs (9/10). Enter 0 if none of those apply.

Boxes 5–8 — Northern Ireland (leave blank)

These four boxes relate to a separate Northern Ireland Corporation Tax rate that doesn't yet exist. HMRC's guidance says to leave all four blank.

About the Return (Boxes 30–90)

These boxes describe the return itself — the period it covers, whether there are special circumstances, and what documents you're attaching.

Box 30 — Period start date

The first day of the accounting period this return covers. Usually the day after your previous financial year ended.

Box 35 — Period end date

The last day of the accounting period. A CT accounting period cannot exceed 12 months.

Box 40 — A repayment is due for this return period

Tick if you expect HMRC to owe your company money — for example, if you overpaid Corporation Tax or received income after Income Tax was deducted at source.

Box 45 — Claim or relief affecting an earlier period

Tick if you're making a claim on this return that reduces tax for a previous year — for example, a trading loss carried back. Most small companies leave this blank.

Box 50 — Making more than one return at the same time

Tick if you're submitting more than one CT return for this company simultaneously. Most small companies leave this blank.

Box 55 — This return contains estimated figures

Tick if any figures are estimates rather than final numbers. HMRC expects final figures wherever possible; if you tick this, they may ask you to amend later.

Box 60 — Company part of a group that is not small

Tick if your company is part of a group (has a parent company or subsidiaries) and that group is not "small". A group is "small" only if it is within all of these limits: fewer than 250 employees worldwide, turnover under approximately £43 million, and a balance sheet total under approximately £37 million. Standalone companies leave this blank.

Box 65 — Notice of disclosable avoidance schemes

Tick only if your company has used a HMRC-notifiable tax avoidance scheme with a Scheme Reference Number. Normal tax planning — claiming capital allowances, pension contributions, dividends — is not a disclosable scheme. Most small companies leave this blank.

Box 70 — Compensating adjustment claimed (transfer pricing)

Relevant only if HMRC has made a transfer pricing adjustment to a connected company and your company is claiming the matching adjustment on its side. Most small companies leave this blank.

Box 75 — Company qualifies for SME exemption (transfer pricing)

Tick to claim exemption from transfer pricing rules because you're a small or medium-sized business. Only relevant if your company has transactions with connected parties. Most small companies leave this blank.

Box 80 — I attach accounts and computations for the period

Tick to confirm you're submitting your company accounts and tax computation for the same period as the return. This is the normal case — almost every company ticks this box.

Box 85 — I attach accounts and computations for a different period

Tick instead of box 80 if the accounts you're attaching cover a different period. Unusual — can happen if you changed your accounting year end.

Box 90 — If not attaching accounts, explain why

If you ticked neither box 80 nor box 85, explain why here. Rare — HMRC expects accounts with every return.

Supplementary Page Indicators (Boxes 95–144)

These tick-boxes signal that you're completing one of the CT600 supplementary pages. Leave them blank if none apply. Most small companies leave all of these blank.

Box 95 and CT600A in practice: Most owner-managed companies are "close companies" (controlled by 5 or fewer participators). If the company made loans or advances to a director or shareholder during the period and those loans are still outstanding at the period end, you tick box 95, complete CT600A with the loan details, and the resulting S455 tax charge (33.75% of the outstanding balance) flows into box 480 on the main form. The S455 tax is refundable when the loan is repaid.

Income (Boxes 145–235)

These boxes capture all the different types of income your company earned. For most small trading companies, only boxes 145, 155, 160, 165, and perhaps 170 need figures.

Box 145 — Total turnover from trade

Your company's total gross revenue (sales) for the period — the top line of your profit and loss account, before expenses. If you're VAT-registered, enter the VAT-exclusive figure. Financial companies without a recognised turnover figure use box 150 instead.

Box 150 — Financial concerns with no recognised turnover

Tick if your company is a bank, building society, insurance company, or similar financial institution that doesn't report a standard turnover figure.

Box 155 — Trading profits

Your company's taxable trading profit — not the same as your accounting profit. You adjust accounting profit by:

• Adding back disallowable expenses (depreciation, client entertaining, non-business costs)
• Deducting capital allowances (the tax version of depreciation)

This is the tax-adjusted trading profit as defined in Part 3 of the Corporation Tax Act 2009.

Example: Accounting profit £50,000 + depreciation £3,000 − capital allowances £4,000 = taxable trading profit £49,000.

Box 160 — Trading losses brought forward set against trading profits

If your company has unrelieved trading losses from earlier periods, enter the amount you want to set against this period's trading profits (box 155) here. Cannot exceed box 155. For post-April 2017 losses you want to set against total profits, use box 285 instead.

Box 165 — Net trading profits (box 155 minus box 160)

Calculated automatically: box 155 minus box 160. Enter 0 if they are equal; leave blank if box 155 is blank.

Box 170 — Bank interest and profits from non-trading loan relationships

Interest your company earned on bank accounts, loans it has made to others, and other non-trading financial instruments, minus any non-trading interest paid. For most small companies, this is simply bank interest received on the business account.

Example: Your business account earned £250 in interest — enter 250.

Box 172 — Tick if box 170 is net of a deficit carried back from a later period

Rare — tick if the figure in box 170 has already been reduced by a non-trading loan deficit carried back from a future accounting period. Most small companies leave this blank.

Box 175 — Annual payments not charged to CT and with no Income Tax deducted

Covers specific recurring payments received that aren't trading income or interest — for example, certain patent royalties. Rare for small companies.

Box 180 — Non-exempt dividends from non-UK resident companies

Dividends received from overseas companies where the dividend exemption doesn't apply. Most overseas dividends are exempt; leave blank if your company doesn't hold overseas shares.

Box 185 — Income from which Income Tax has been deducted

Income where the payer already deducted Income Tax before paying you. Enter the gross amount; the tax deducted goes in box 515 as a credit against your CT bill.

Box 190 — Income from a property business

Net rental income from property your company owns, after deducting allowable expenses (repairs, insurance, letting agent fees, mortgage interest). If your property business made a loss, use box 805 instead.

Box 195 — Non-trading gains on intangible fixed assets

Profit from selling intangible assets (patents, trademarks, copyrights, goodwill) where the disposal isn't part of your main trade. Most small companies leave this blank.

Box 200 — Tonnage tax profits

Shipping companies in the tonnage tax regime only.

Box 205 — Income not falling under any other heading

Any other taxable income not captured above — for example, certain UK dividends that aren't exempt, or income from a discontinued business.

Box 210 — Gross chargeable gains

Total capital gains from selling capital assets — property, shares, business goodwill — before deducting capital losses. Leave blank (along with boxes 215 and 220) if no capital disposals occurred.

Box 215 — Allowable losses including losses brought forward

Capital losses to set against box 210. Cannot exceed box 210. Leave blank if box 210 is blank.

Box 220 — Net chargeable gains (box 210 minus box 215)

Calculated automatically: box 210 minus box 215. Enter 0 if equal.

Box 225 — Losses brought forward against certain investment income

A narrow relief under CTA 2010 s.46 — old trading losses set against specific income the law treats as if it were trading income (e.g. certain mineral royalties). Does not apply to bank interest, rental income, or dividends. Most small companies leave this blank.

Box 230 — Non-trade deficits on loan relationships brought forward set against non-trading profits

Old deficits on non-trading loan relationships from earlier periods, used to reduce this period's non-trading income. Most small companies leave this blank.

Box 235 — Profits before other deductions and reliefs

Calculated automatically: net sum of boxes 165 to 205 and 220, minus boxes 225 and 230. This is your total profits before the further deductions in the next section.

Deductions and Reliefs (Boxes 240–315)

These boxes reduce your taxable profits further, arriving at the figure that Corporation Tax rates are applied to.

Box 240 — Losses on unquoted shares

Relief for losses on shares in unquoted trading companies under CTA 2010 s.68. Very niche.

Box 245 — Management expenses

Costs of managing investments for investment companies. Trading companies leave this blank.

Box 250 — UK property business losses

Losses from your company's UK rental/property business being set against total profits this period.

Box 255 — Capital allowances for management of the business

Capital allowances on assets used for investment management. Not for trading companies.

Box 260 — Non-trade deficits on loan relationships this accounting period

If your company's non-trading loan relationships produced a net deficit this period, enter it here.

Box 263 — Carried-forward non-trade deficits on loan relationships

Unused post-April 2017 non-trade loan relationship deficits from earlier periods, claimed against total profits this period.

Box 265 — Non-trading losses on intangible fixed assets

Non-trading losses on intangible assets being set against profits.

Box 275 — Total trading losses of this or a later accounting period

If your company made a trading loss this period (or you're carrying back a loss from a later period), enter the total here.

Box 280 — Tick if box 275 includes amounts carried back from later periods

Tick if any of the loss in box 275 was carried back from a future accounting period.

Box 285 — Trading losses carried forward claimed against total profits

Post-April 2017 trading losses from earlier periods set against total profits (not just trading profits) this period. This is the main box for deploying pre-existing trading losses. See our losses carry-forward guide.

Box 290 — Non-trade capital allowances

Capital allowances on assets not used in a trade.

Box 295 — Total of deductions and reliefs (boxes 240 to 275, 285, and 290)

Calculated automatically.

Box 300 — Profits before qualifying donations and group relief (box 235 minus box 295)

Calculated automatically.

Box 305 — Qualifying donations

Total qualifying charitable donations made by the company during the period. These reduce taxable profits pound for pound.

Box 310 — Group relief

Losses surrendered from other group companies to reduce this company's profits. Only for company groups.

Box 312 — Group relief for carried-forward losses

Carried-forward losses surrendered via group relief from another group company.

Box 315 — Profits chargeable to Corporation Tax (PCTCT)

The key figure. Calculated as box 300 minus boxes 305, 310, and 312. This is the profit that Corporation Tax rates are applied to — everything above has been building towards this number.

Tax Calculation (Boxes 326–475)

These boxes apply the correct tax rates and reliefs to arrive at your net Corporation Tax liability.

Boxes 326–328 — Associated companies

Three boxes record how many associated companies (companies under common control) existed during the period:

• Box 326: Number of associated companies in this period
• Box 327: Number in the first financial year (if your period spans two tax years)
• Box 328: Number in the second financial year

Why this matters: The £50,000 small profits threshold and the £250,000 main rate threshold are each divided by (1 + number of associated companies). With one associated company, each company's thresholds halve: small profits threshold drops to £25,000, main rate threshold drops to £125,000. Enter 0 if you have no associated companies. See our associated companies guide.

Box 329 — Tick if the company is chargeable at the small profits rate or entitled to marginal relief

Tick if your company's augmented profits — taxable profits (box 315) plus any dividends received from other UK companies (box 620) — are at or below the adjusted upper threshold. The adjusted upper threshold is £250,000 divided by (1 + number of associated companies), then prorated for accounting periods shorter than 12 months. For example, a company with one associated company has an upper threshold of £125,000; box 329 would be ticked only if augmented profits are £125,000 or less. A company with PCTCT of £120,000 but £10,000 of UK dividends (box 620) has augmented profits of £130,000 — exceeding the £125,000 threshold, so box 329 would not be ticked. Software calculates this automatically.

Boxes 330–425 — Financial year rows

Corporation Tax financial years run 1 April to 31 March. If your accounting period spans two financial years, profits and rates must be apportioned:

• Box 330 — Financial Year 1 (e.g. FY2024 = 1 April 2024 to 31 March 2025)
• Box 335 — Profit apportioned to FY1
• Box 340 — FY1 rate of tax
• Box 345 — FY1 tax

FY2 rows run from box 380. For a period falling entirely within one financial year, only the FY1 rows are used.

Box 430 — Corporation Tax (total of all FY rows)

The sum of all financial year tax amounts. This is total Corporation Tax before marginal relief.

Box 435 — Marginal relief

The marginal relief amount. Applies when your PCTCT (adjusted for associated companies and period length) falls between £50,000 and £250,000. Formula: 3/200 × (upper limit − augmented profits) × (PCTCT / augmented profits). This tapers the effective rate from 25% towards 19% as profits approach the lower threshold.

Box 440 — Corporation Tax chargeable (box 430 minus box 435)

Your Corporation Tax after deducting marginal relief:

• Profits at or below £50,000 (adjusted): 19% rate
• Profits above £250,000 (adjusted): 25% rate
• Profits in between: effective rate between 19% and 25% after marginal relief

Box 445 — Community Investment Tax Relief

Relief for investments in accredited Community Development Finance Institutions. Rare for most small companies.

Box 450 — Double Taxation Relief

Relief to avoid being taxed twice on overseas income — if your company paid foreign tax on income also taxable in the UK.

Box 465 — Advance Corporation Tax

ACT was abolished in 1999. Shadow ACT claims may still arise for companies with pre-1999 surplus ACT. Most small companies leave this blank.

Box 470 — Total reliefs and deductions in terms of tax

Sum of boxes 445, 450, and 465.

Box 475 — Net Corporation Tax liability (box 440 minus box 470)

Corporation Tax after all reliefs. For most small companies with no special reliefs, this equals box 440.

Tax Payable (Boxes 480–605)

These boxes handle additional charges, credits, and adjustments to arrive at the final self-assessed tax payable or repayable.

Box 480 — Tax payable on loans and arrangements to participators

If you ticked box 95 and completed CT600A, the S455 tax charge (33.75% of outstanding loans at the period end) flows here from box A80 of CT600A. Payable 9 months and 1 day after the period end, like the main Corporation Tax.

Box 510 — Tax chargeable

Total tax chargeable: box 475 plus box 480 and any other specific charges (CFC tax, bank levy, RPDT, energy levies, ring fence supplementary charge). For most small companies, this equals box 475.

Box 515 — Income Tax deducted from gross income included in profits

Income Tax deducted at source from income received by your company. Enter the amount deducted; it's a credit against your Corporation Tax.

Box 525 — Self-assessment of tax payable

Box 510 minus box 515. Your self-assessed Corporation Tax payable.

Box 528 — Self-assessment of tax payable (total)

Box 525 plus any coronavirus support scheme overpayment (box 526) and restitution tax (box 527). For most companies, this equals box 525.

Boxes 530–565 — Tax credits

These boxes cover various tax credits:

• Box 530: R&D tax credit
• Box 540: Creatives tax credit
• Box 541: Audio-Visual expenditure credit (AVEC) / Video Games expenditure credit (VGEC)
• Box 545: Total of R&D, creatives, AVEC/VGEC
• Box 550: Land remediation tax credit
• Box 565: Capital allowances first-year tax credit

R&D and creative credits require the relevant supplementary pages. Most small companies leave these blank.

Boxes 570–580 — Payable credits (surplus amounts)

Where credits exceed the Corporation Tax liability, the surplus can be paid out: box 570 for surplus R&D/creatives credits, box 575 for surplus land remediation credits, box 580 for surplus first-year tax credits.

Box 595 — Tax already paid

Corporation Tax already paid for this period and not already repaid — for example, payments on account.

Box 600 — Tax outstanding

The remaining Corporation Tax still to pay. Broadly box 525 minus credits (boxes 545, 560, 565) and prior payments (box 595). This is the amount due to HMRC by the payment deadline — 9 months and 1 day after your period end for non-large companies.

Box 605 — Tax overpaid

If credits and payments exceed your liability, this is the repayment amount due to your company.

Capital Allowances (Boxes 688–775)

These boxes detail your capital allowance claims. Capital allowances are the tax-deductible equivalent of depreciation — you claim allowances on qualifying assets at HMRC-set rates instead of accounting depreciation (which is disallowable). The total allowances feed into your box 155 trading profits calculation.

Box 688 — Full expensing — capital allowances

100% first-year allowance on new, unused main-rate plant and machinery purchased by companies. Full expensing became permanent from April 2023 and applies to companies only (not unincorporated businesses).

Box 689 — Full expensing — balancing charges

Where full-expensed assets are later sold or disposed of, the proceeds are treated as a balancing charge.

Box 690 — Annual Investment Allowance (AIA)

The AIA gives 100% relief in the year of purchase for qualifying plant and machinery, up to £1,000,000 per year (prorated for accounting periods shorter than 12 months). Most small companies use the AIA for all equipment purchases.

Boxes 693/694 — Full expensing (special rate) — allowances and charges

50% first-year allowance on new, unused special-rate plant and machinery under full expensing (box 693 for allowances, box 694 for balancing charges on disposal). Special-rate assets are integral building features (electrical systems, heating, lifts, escalators) and long-life assets. Do not include these amounts in boxes 695 or 700.

Boxes 695/700 — Special rate pool — allowances and charges

6% writing-down allowances (box 695) and balancing charges (box 700) on the special rate pool — integral features (electrical systems, central heating, lifts), long-life assets, and thermal insulation. Do not include amounts entered in box 693.

Box 705 — Machinery and plant main pool — allowances

18% writing-down allowances on the main pool of plant and machinery — assets not covered by AIA or full expensing in the year of purchase.

Box 710 — Machinery and plant main pool — charges

Balancing charges when main pool disposals exceed the pool balance.

Box 711 — Structures and buildings allowance (SBA)

3% straight-line allowance per year on the cost of constructing or buying new non-residential buildings and structures (for expenditure from October 2018 onwards).

Losses (Boxes 780–855)

This section summarises losses arising in the period. They feed both the deduction boxes (240–285) and amounts available to carry forward or surrender as group relief.

Box 780 — Losses of trades carried on wholly or partly in the UK

If your company made a trading loss this period, enter the total amount here. This is the figure available to carry back, carry forward, or surrender as group relief.

Box 785 — Maximum available for surrender as group relief

The portion of box 780 that can be surrendered to another group company. Only for company groups.

Box 795 — Non-trade deficits on loan relationships

If your company had a net deficit on its non-trading loan relationships this period, enter the amount here.

Box 805 — UK property business losses

Losses from your UK property rental business not used against total profits — available to carry forward.

Box 825 — Capital losses

Capital losses from asset disposals this period. Capital losses can only be set against capital gains (box 215) — they cannot reduce trading profits.

Payments and Repayments (Boxes 860–940)

Box 865 — Repayment of Corporation Tax

The amount of Corporation Tax you're requesting HMRC to repay (when box 605 shows an overpayment).

Box 870 — Repayment of Income Tax

Income Tax deducted at source to be repaid because it exceeds your Corporation Tax liability.

Boxes 875–886 — Payable credits

Where R&D, creatives, or other tax credits exceed your tax liability, the surplus is paid to your company:

• Box 875: Payable R&D tax credit
• Box 880: Payable R&D expenditure credit (RDEC)
• Box 885: Payable creatives tax credit
• Box 886: Payable AVEC/VGEC

Boxes 920–940 — Bank details

Your company's bank account for any repayment:

• Box 920: Bank or building society name
• Box 925: Branch sort code
• Box 930: Account number
• Box 935: Account name
• Box 940: Building society roll number (if applicable)

Declaration (Boxes 975–985)

Box 975 — Declarant name

The name of the person signing the return — usually the company director for a small company.

Box 980 — Date of declaration

The date the return was signed.

Box 985 — Status

The declarant's position — for example, "Director" or "Company Secretary".

Which Boxes Do Most Small Companies Actually Use?

For a typical small limited company — single trade, no property income, no investments, no group, no directors' loans — here's the realistic list:

That's around 20 boxes. Everything else stays blank.

Filing Tips

Don't panic about blank boxes

The CT600 is designed for every type of company — from single-director micro-entities to multinational corporations. Most boxes don't apply to you. Blank boxes are normal and expected.

Cross-check your figures

A few key relationships should hold:

• Box 145 (turnover) is the starting point for your trading profit calculation
• Box 155 (trading profits) is the tax-adjusted figure — not the same as box 145
• Box 315 (PCTCT) = box 235 minus all deductions; this is what gets taxed
• Box 440 (CT chargeable) ≈ box 315 × applicable rate (19% or 25%), adjusted for marginal relief
• Box 600 (tax outstanding) = box 525 minus any credits and payments already made

If these don't reconcile, something has gone wrong.

Use software

Filing software like Taxpipe handles the box cross-references for standard income types automatically — trading profits, bank interest, property income, capital gains, and capital allowances. Enter your income and expenses in the guided wizard and the relevant boxes are populated for you. It costs £59 per filing with direct HMRC submission.

Frequently Asked Questions

Do I need to fill in every box on the CT600?

No. Most small companies use fewer than 20 boxes. Leave irrelevant boxes blank — HMRC expects this for simple returns.

What's the difference between box 145 and box 155?

Box 145 is your turnover (total sales revenue before any costs). Box 155 is your taxable trading profit — turnover minus allowable expenses, with depreciation added back and capital allowances deducted. Your Corporation Tax is calculated on profit (box 155 and downstream), not on turnover.

What goes in box 145 — gross turnover or net?

Gross turnover (total sales/revenue before deducting any expenses). If you're VAT-registered, enter the VAT-exclusive figure.

Why do boxes 440, 475, 510, and 525 all seem to show the same number?

For a simple return with no double taxation relief, no S455 charges, no payable credits, and no Income Tax at source, the same figure flows through all four boxes. Each box applies a different layer: box 440 is after marginal relief, box 475 is after tax reliefs (e.g. double taxation), box 510 adds any extra charges (S455, CFC tax), box 525 deducts Income Tax withheld at source. When none of those extra layers apply, the figure stays the same throughout.

What if I have bank interest — which box?

Bank interest goes in box 170 (bank, building society or other interest, and profits from non-trading loan relationships). It flows into box 235 as part of total profits before deductions and ultimately into box 315 (PCTCT). See our full guide: Corporation Tax on Bank Interest: How It Works.

What is box 315 — PCTCT?

PCTCT stands for "Profits Chargeable to Corporation Tax". It's the final taxable profit figure — after all income has been added and all deductions, losses, donations, and group relief have been applied. Corporation Tax rates are applied to this number.

What is marginal relief and when does it apply?

Marginal relief applies when your augmented profits — taxable profits (box 315) plus any dividends received from other UK companies (box 620) — fall between the adjusted lower threshold (£50,000) and upper threshold (£250,000), after dividing by (1 + associated companies) and prorating for the length of the accounting period. The standard rate is 25%, but marginal relief tapers the effective rate down towards 19% as profits approach £50,000. The full formula is: 3/200 × (upper limit − augmented profits) × (PCTCT ÷ augmented profits), where the upper limit is £250,000 divided by (associated companies + 1), prorated for short accounting periods. For a company with no associated companies and a full 12-month period, augmented profits equal PCTCT and the formula simplifies to 3/200 × (£250,000 − PCTCT). Box 435 shows the relief amount; box 440 is the CT chargeable after deducting it. See our full marginal relief guide for worked examples.

Don't want to figure out hundreds of boxes manually? File with Taxpipe — our guided wizard asks simple questions and handles the Corporation Tax calculation for standard trading companies. Direct HMRC submission, just £59.

Related Articles

• CT600 Box by Box Guide: Every Section Explained in Plain English
• CT600 Supplementary Pages Explained: Which Ones Does Your Company Need?
• Filing a CT600 for a Dormant Company — Complete Guide
• Directors' Loan Accounts and Your CT600 — What Every Director Needs to Know