26 August 2026 · The Register
A CT-Ready Fixed-Asset Register
A corporate-tax-ready fixed-asset register lists every capital asset with its original cost, the date it entered service, the depreciation taken each period, and a running tax written-down value. For fair-valued investment property it sits alongside the IAS 40 accounts, because those record no depreciation. Without it, you cannot support a deemed depreciation claim under Ministerial Decision 173 of 2025 or defend your deductions in an FTA review.
Exiloz Management & Tax Consultant · Dubai-based FTA-focused advisory · VAT, corporate tax & accounting
A tax register proves how the balance moved
A fixed-asset register is the running record behind the corporate tax calculation. For each relevant asset, show original cost, the date it entered service, additions, disposals, tax depreciation or deemed depreciation claimed, and the tax written-down value. For fair-valued investment property, keep this record beside the financial statements because the accounting balance and the tax basis answer different questions.
Example: a qualifying fair-valued investment property has original cost of AED 2,100,000. AED 2,100,000 x 4% = AED 84,000. If opening TWDV is AED 75,000, the lower deduction is AED 75,000, and closing TWDV is AED 75,000 - AED 75,000 = AED 0. The register makes the cap visible instead of leaving it inside a formula that nobody can trace.
The example shows why one asset list is not enough. Original cost is not fair value, the period claim is not automatically the book depreciation line, and closing TWDV is not a valuation. Each field has a job. A preparer should be able to follow the amount from invoice to register, from register to reconciliation, and from reconciliation to the Tax Return.
- Preserve original cost.
- Record the in-service date.
- Track claims by period.
- Roll the TWDV forward.
The register must cover the facts the return uses
Start with the assets in the signed financial statements and general ledger, then mark the items treated differently for tax. Fair-valued investment property needs its own flag because MD 173 uses original cost and TWDV, while IAS 40 accounts may show a fair-value balance with no depreciation charge. One column should not carry both bases. If it does, the register hides the exact difference the return needs explained.
The register is not limited to buildings. It can cover equipment, vehicles, furniture, leasehold improvements, software, and capitalised additions where the accounting and tax treatment must be followed. The supporting object changes by asset: invoice, handover record, contract, capitalisation schedule, disposal agreement, or transfer document. The source should be identified on the line, not left in an unindexed folder.
The mistake we see most is presenting a list of descriptions and net book values as a tax register. That list may show what the accounts carry, but it cannot prove original cost, opening TWDV, a period claim, or a disposal. Before a deduction is carried forward, ask for the acquisition documents and accounting policy. This is an evidence problem, not a formatting problem.
- Flag fair-value property.
- Separate book and tax columns.
- Link every addition to a source.
- Keep disposals visible.
What belongs in the working paper
The core fields are asset description, asset class, original cost, date placed in service, entity, additions, disposals, tax depreciation claimed, opening TWDV, current-period deduction, and closing TWDV. Put the source reference beside each line rather than in a separate folder with no index. The aim is not a polished schedule. It is a traceable one that another preparer can reproduce from the underlying documents.
For MD 173 property, preserve the signed financial statements, fair-value accounting policy, purchase agreement, capitalised-cost support, Tax Return containing the election, and realisation records. MD 173 says original cost includes subsequent capitalised costs subject to the arm's-length principle in Article 34. The register therefore needs an additions trail. The first purchase price alone cannot explain the tax basis after later work is capitalised.
The format has an unsettled boundary. MD 173 defines original cost, opening value, and TWDV, but it does not specify a spreadsheet layout or name every internal control field. The FTA Corporate Tax FAQ says records must support information in the Tax Return. A register is the practical translation of that requirement, not an official FTA form. Label it as a working paper and keep its assumptions visible.
- Index the source document.
- Keep additions separately supported.
- Show opening and closing TWDV.
- Tie the file to the return.
Update the register when the asset changes
Update the register when an asset is acquired, placed in service, improved, transferred, disposed of, or moved between accounting models. Record the date and document for the change, then recalculate the tax basis before the next return working paper is closed. A register prepared only at year end is often a reconstruction of decisions made months earlier, after the person who made them has moved on.
We would build the register from acquisition documents and approved capitalisation records, not by copying the net book value column from the general ledger. The ledger answers the accounting question, while MD 173 asks for original cost, opening value, and the claimed tax deduction. Starting from the source preserves that distinction before the reconciliation is drafted and before a disposal disappears into a closing balance.
If the filing date is close, prioritise the assets that create the return adjustment: fair-valued investment property, recent capitalised additions, disposals, and transfers. Mark uncertain lines and locate the document that resolves each one. A short list of named exceptions is more useful than a long register that quietly guesses its opening values. The unresolved list should travel with the return file.
- Update after every acquisition.
- Record transfers and disposals.
- Reconcile before the return.
- Mark unresolved lines openly.
The number of assets is only one cost driver
The work grows with the number of entities, asset lines, additions, disposals, currencies, and inherited periods in the file. It also grows when the general ledger has pooled assets, invoices are missing, or a property changed from fair value to cost. These conditions determine the tracing and reconstruction time. A sensible scope describes that workload instead of hiding it behind a package label.
The table gives a decision matrix for the file in front of you. A usable register answers the tax question and points to the source. A partial register may show a balance but not the basis. A pooled balance hides the individual history. A disposal line without its agreement can leave the realisation treatment unsupported. Each state calls for a different next action, and each action changes the review time.
Exiloz can build or clean the register and connect it to the tax reconciliation. The service does not include a statutory audit. Exiloz does not perform statutory audits, is not a registered Tax Agent, and is not an FTA-accredited e-invoicing Service Provider. The deliverable is a tax-supporting record with source references, period calculations, and a clear handoff to the return preparer.
- Asset volume sets tracing time.
- Pooled balances need separation.
- Missing invoices require source work.
- Disposals need their own evidence.
| Register state | Question to answer | Next action |
|---|---|---|
| Line-by-line with sources | Can cost, dates, claims, and TWDV be traced? | Reconcile to the Tax Return |
| Lines without source references | Which document proves each amount? | Locate invoices and agreements |
| Pooled assets in one balance | Can individual bases be identified? | Split the asset history |
| Disposed asset still open | Has the closing event been recorded? | Attach the disposal record |
Frequently Asked Questions
For finance and tax teams.
What is a fixed-asset register for corporate tax?
It is a record of every capital asset held for the business, showing original cost, in-service date, depreciation claimed and the running tax written-down value. It supports the depreciation and capital deductions taken on the corporate tax return.
Why keep original cost when the accounts use fair value?
Because tax depreciation is based on original cost, not the revalued fair-value figure. The register keeps the cost basis and tax written-down value that the IAS 40 accounts do not, so your deduction can be computed and defended.
Does the FTA require a fixed-asset register?
The corporate tax law requires you to keep records that support your return. A fixed-asset register is the practical way to evidence depreciation and capital deductions, and it is the first thing a reviewer asks for.
What is tax written-down value?
It is the asset's original cost less the depreciation claimed for tax to date. It caps the deemed depreciation deduction and sits at the centre of a corporate-tax-ready register.
How is it different from the accounting asset ledger?
The accounting ledger follows your IFRS policy, which for investment property means fair value and no depreciation. The tax register keeps cost and a tax written-down value instead, and the two are reconciled rather than merged.
Can Exiloz build our register?
Yes. We construct a corporate-tax-ready fixed-asset register from your records, set the tax written-down values, and maintain it alongside your accounts.
Build a register that holds up
Exiloz builds and maintains a corporate-tax-ready fixed-asset register that supports every deduction.