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Destroying NBA working papers: what can go after 7 years?

Every spring, accountancy firms hit the same moment. The year whose tax retention period is about to expire. Seven years of working papers, audit memoranda, trial balances and client correspondence sit waiting for disposal. But what really can go, and what still has to stay? This article lines up the frameworks from art. 52 AWR, the NBA professional rules and GDPR art. 5(1)(e).

Written for the office manager, the compliance officer and the technical bureau of mid-sized and smaller accountancy practices.

The 7-year line in the AWR

Art. 52 AWR requires bookkeeping-obligated persons to keep their administration for seven years. For accountants this applies twice over. First, for their own administration; second, as a derived obligation from the client file in which fiscally relevant documents are stored. After seven full years the basic retention period lapses, unless there are exceptions.

Important exception: administration around real estate has a retention period of nine years (VAT adjustment period). So do not close a file with real-estate transactions too early.

NBA: at least seven years, sometimes longer

The NBA Regulation on professional conduct and the supplementary rules on the audit file prescribe that the audit file is kept for at least seven years, calculated from the date of the audit opinion. For Wta-licence holders this period extends in specific situations. Wwft-related client-due-diligence documents have their own period of five years after the end of the business relationship.

Concretely: the fiscal seven years are the floor. The actual retention obligation may be longer depending on client type, audit engagement and the nature of the transactions. Read the details in our background article the 7-year tax retention obligation.

So what may then go?

Once the longest applicable term has expired, a document may and must be destroyed. GDPR art. 5(1)(e) (storage limitation) is not a friendly recommendation but an obligation: personal data may not be kept longer than necessary.

Always keep the destruction decision file-bound. A blanket "anything older than seven years goes" rule is too coarse. It overlooks precisely the real-estate, Wwft and pending-dispute exceptions.

What must stay?

How to destroy: the practice

Working papers contain BSNs, financial data, commercially sensitive information and sometimes special categories of personal data. That raises the destruction bar to DIN 66399 P-5 for paper and H-4 or E-4 for media. An office paper shredder usually does not reach that standard.

On-site mobile document destruction is a logical route for accountancy firms. The boxes go straight out of the archive cabinet and into the shredder on the car park, with no intermediate step where a client file sits in a truck on the A10. Immediately after completion you receive a certificate that you can file in your quality system as evidence of storage limitation.

2018 vintage ripe for destruction?

We come with a mobile shredder to your office in Amsterdam-Noord or the immediate vicinity. DIN 66399 P-5, certificate per job, you watch along. No contract, no minimum.

Request a quote

Documentation and quality file

Record the destruction in the firm's destruction register: which vintage, which document type, which method, which processor, which certificate number. The NBA quality system and any AFM inspection want to see that you not only retain but also clear out. A well-maintained destruction register is the evidence.

More background on accountancy practice at DeSnipperaar is on our accountants industry page.


In short: seven years is the tax floor, nine years applies to real estate, five years after end of relationship for Wwft. What is past those terms may not only go, it must go under the GDPR. Destroy in a controlled way, on-site, with a certificate. That is how you close the vintage properly.