Authorising your bookkeeper with the tax authorities
Written by Ilias Aarrass5 min read · Published on · Last reviewed on 
In short
Your bookkeeper never needs your personal or business login: a sole trader arranges an authorisation through the personal register that applies per tax year, for a company your adviser requests a chain authorisation via the business login system, and responsibility for the return stays with you.
- Login credentials are personal and may not be lent out, not even to an adviser you trust.
- Allow about a week before an authorisation for your return is in place.
- With service messages your adviser receives your assessments digitally, so an error does not become final unnoticed.
- Deferral through the scheme for tax professionals is not automatic and does not postpone tax interest.
If you have a bookkeeper file your returns, the first practical question is how they access your data. The answer is not: hand over your login. That is not allowed and not necessary, because there are official ways to authorise someone. Which way depends on your legal form and on what you have them do. This article covers how it works for a sole trader and for a company, how deferral through your bookkeeper works and what responsibility stays with you, however good your adviser is.
Never hand over your own login details
Your personal and business login credentials are personal. You may not lend them out, not even to someone you trust completely, and in case of misuse you are the one with a problem. That is no formality: with your personal login someone can also reach your allowances, your medical records and your pension overview. That is why separate authorisation routes exist for anyone acting on your behalf.
In practice your bookkeeper often does not use your account at all. Tax professionals usually file returns with professional software that communicates directly with the tax authorities. Then no login of yours is needed, but your instruction and your approval of the documents are.
Sole trader: authorising via the personal authorisation register
If you have a sole trader business, your income tax return runs through your personal details. If you want your bookkeeper to be able to file or view that return, you arrange it through the personal authorisation register. You request the authorisation, or your bookkeeper does and you confirm it. Allow about a week before it is in place, and note that such an authorisation applies per tax year: so you renew it annually.
For your VAT return and other business matters your bookkeeper usually uses their own software or a chain authorisation based on the business login system. If you need that business login yourself, for example to look into the business portal, applying for the business login as a freelancer explains how that works and what it costs.
| Situation | Route |
|---|---|
| Sole trader, income tax return | the personal authorisation register, per tax year |
| A company or other legal form | chain authorisation via the business login, requested by your adviser |
| Having your VAT return filed | usually through your bookkeeper's software |
| Having allowances arranged | a separate authorisation for allowances |
| Having an objection filed | an authorisation or a signed power of attorney with the objection |
Service messages and the deferral scheme
Two things your bookkeeper can arrange that take work off your hands. The first are service messages: your adviser then receives digital copies of your assessments and decisions, so they can check them without you forwarding everything. That prevents an assessment with an error becoming final unnoticed; see objecting to an assessment.
The second is the deferral scheme for tax professionals. Bookkeepers with a professional registration number can request collective deferral for their clients' income tax returns, so you can file much later than the usual deadline. That is handy if your paperwork is incomplete, but it does not mean you pay later: tax interest runs independently of your deferral. See filing late and requesting deferral and avoiding tax interest.
What to arrange with a new bookkeeper
- Step 1
- an engagement letter setting out what they do and what you supply
- Step 2
- authorisation for the return, per tax year for a sole trader
- Step 3
- switch on service messages so they see your assessments
- Step 4
- deferral via the professional scheme if you want it
- Step 5
- agree who files the VAT return and who pays
Result: With those five points on paper you know exactly who does what. What else you need to supply is in [outsourcing your bookkeeping: what to hand over](kb:boekhouding-uitbesteden-wat-lever-je-aan).
You remain responsible
An authorisation shifts the work, not the responsibility. The return remains your return: if something is wrong, you receive the assessment and any penalty. So always read the return and the annual figures before you approve, and ask for an explanation of items you do not recognise. A good bookkeeper is happy to explain, because they also have an interest in the figures being right.
If you end the relationship, withdraw the authorisation and ask for a complete export of your records. That is the moment to check you have everything, because later it is much harder; see switching bookkeepers and backing up and exporting your bookkeeping.
- Never lend out your personal or business login, not even to your adviser.
- Arrange the authorisation in time; for a sole trader that takes about a week.
- Renew the authorisation annually, because it applies per tax year.
- Switch on service messages, so an error in an assessment does not become final.
- Read the return yourself before you give approval.
Frequently asked questions
Can my bookkeeper use my personal login?
No. Login credentials are personal and may not be lent out. There are official authorisation routes, and in practice your bookkeeper usually works with their own professional software.
Do I get automatic deferral if my bookkeeper files my return?
Not automatically: your bookkeeper has to register you for the deferral scheme for tax professionals. So ask explicitly, and bear in mind that tax interest can accrue regardless of the deferral.
Sources
- Help with logging in and authorisation for entrepreneursBelastingdienst · belastingdienst.nl
- The personal authorisation registerDigiD · machtigen.digid.nl
- How the business login worksBelastingdienst · belastingdienst.nl
Sources checked on
This article provides general information based on the rules known for 2026 and does not replace personal tax advice. For your specific situation, we're happy to take a look with you.
