Comparing fiscal software
Which fiscal software fits your practice?
Short answer: pick a full filing suite for VAT, personal tax, corporate tax and payroll in one system, a specialist tool such as Lowkey for one specific procedure without an implementation project, and general AI only for text and research, never for filling in forms with client data. Lowkey is explicitly not a full filing suite.
| Full filing suite | General AI / LLM | Specialist tool (Lowkey) | |
|---|---|---|---|
| What it does | All procedures: VAT, personal tax, corporate tax, payroll in one system | Generates free text in response to questions | One specific fiscal procedure from data entry to filled form and cover letter |
| End product | Complete filing, ready to submit | Text and answers, no form output | Filled Dutch tax authority form plus letter on your own letterhead |
| Output quality | Structured and repeatable per vendor | Non-deterministic: same question, varying answer | Deterministic: same input always produces the same document |
| Client data and GDPR | Varies by vendor, often NL or EU | Varies widely; many vendors process outside the EU | EU only; uploads processed in memory and discarded |
| Pricing | Licence or subscription, often per user or per firm | Per-user subscription or per-token pricing | € 39 per finished document, excl. VAT; no seats |
| Setup | Longer onboarding, integration with existing systems | No setup, but no guaranteed output either | No installation; create an account and start |
| Scope | Broad: replaces multiple systems | Broad but shallow on specialist tasks | Narrow: five procedures, done completely |
Full filing suite: full coverage, larger investment
A full filing suite is the right choice when your practice needs an integrated system for almost every fiscal procedure. VAT returns, personal income tax, corporate tax, payroll taxes: everything in one place, connected to your own administration. The licence and implementation costs are substantial. That investment pays off when the usage is broad enough across your team.
Lowkey is not a replacement for a full suite. If your practice already uses one, Lowkey fills the gap for procedures that are either missing or require too much manual work inside it: the 30% ruling application, the fiscal unity request for corporate tax, and ATAD2 hybrid-mismatch analysis.
General AI: good for text, unsuitable for forms
General AI models do well at summarising documents, answering open questions, and drafting memos. They are not built for the specific forms and calculation rules of the Dutch tax authority (Belastingdienst).
Three concrete problems for tax applications:
- The same question can produce a different answer the next day.
- The end product is free text, not a filled form. You still have to translate that output into the correct official format yourself.
- Client data sent to a general chatbot may be processed by vendors outside the EU, with varying retention policies per provider.
For general research or exploring public legislation, general AI tools are useful. For the form work of a procedure with client data, they are not the right fit.
Specialist procedure tool: one procedure, fully finished
A specialist tool handles a limited number of procedures and does them completely. Lowkey automates three specific tasks:
- 30% ruling application with cover letter
- Fiscal unity request for corporate tax, Part A and Part B
- ATAD2 hybrid-mismatch analysis (via hybridmismatch.com)
The calculation and form-filling run on fixed rules, not a language model. The same input always produces the same document. A model at most reads a messy upload so you do not have to retype anything; it never determines the output.
When does a specialist tool win?
A specialist procedure tool is a good fit when one or more of the following apply:
- Your current software does not cover a specific procedure, or it requires too much manual work to keep documents consistent across multiple fields.
- Client data must stay in the EU: either by your firm's own data policy or at the client's request.
- You do not want to manage a new seat-licence system for procedures you run a handful of times per month.
- You want to automate a specific procedure without replacing or re-implementing your whole stack.
Lowkey is not a full suite. If your practice needs to automate VAT returns, personal income tax returns, or the full corporate tax return, you need a broader solution.
What Lowkey covers and what it does not
| Yes | 30% ruling application with cover letter on your own letterhead |
| Yes | Fiscal unity request for corporate tax, Part A and Part B, consistent from a single input |
| Yes | ATAD2 hybrid-mismatch analysis via hybridmismatch.com, see the example ATAD2 documentation memo |
| No | VAT returns, personal income tax returns, or the full corporate tax return |
| No | Assessing whether an application will be approved; that judgement stays with your firm |
| No | Filing with the tax authority; you review, sign and submit |
More on how we handle client data: EU & data.
Frequently asked questions
When does a full filing suite make sense?
When your practice needs one integrated system covering all procedures: VAT, personal income tax, corporate tax, payroll taxes and the related reports. Full suites require a larger upfront investment and a longer implementation, but they cover the broadest scope.
What are the risks of using general AI for tax procedures?
General AI models are not built for the specific forms and calculation rules of the Dutch tax authority. The same question can get a different answer, and client data may be processed outside the EU, depending on the provider.
What does Lowkey cover and what does it not cover?
Lowkey automates five procedures: the 30% ruling application, the fiscal unity request for corporate tax and VAT, ATAD2 hybrid-mismatch analysis, and converting annual figures into an RGS bridge file. VAT returns, personal income tax returns, and the full corporate tax return are outside scope.
How does Lowkey handle client data and GDPR?
All processing takes place on EU infrastructure. Uploads are processed in memory and discarded afterwards. A billing record is retained, never the document contents. Your firm remains the data controller. Read how we handle data.
What does a document cost at Lowkey?
€ 39 per finished document, excl. VAT. Nothing to sign up for: no fixed seats, no setup costs. You only pay when a document is produced.