Open Format - the export file your accountant needs
"Send me the Open Format file" is a request every freelancer in Israel hears from their accountant at least once a year, and sometimes directly from the Tax Authority during an audit.
What Open Format is
Open Format (mivneh achid, officially "the uniform structure for transferring accounting data files") is a standard file format set by the Israel Tax Authority. It lets a business transfer all of its accounting data, meaning documents, transactions, customer and supplier records, in one uniform shape that every bookkeeping program and every accountant knows how to read, regardless of which specific software originally produced the data.
- A text file describing the structure
- Which record types exist and in what order
- Small, read first
- The data itself
- Documents, entries, customers and suppliers
- Encoded in ISO-8859-8-I
The two files that make it up
Two files together make up an Open Format export. The INI file is a text file describing the structure: which record types exist in the data file and in what order. The BKMVDATA file is the actual data file, containing every record itself, typically encoded in ISO-8859-8-I, the Hebrew-specific encoding. Both files together, packaged into a single ZIP, are what counts as a complete Open Format file.
Why that old encoding is still here
ISO-8859-8-I is a Hebrew encoding from before the UTF-8 era, kept in the standard for backward compatibility. Older systems reading the file expect exactly that. It's also why an Open Format file opened by accident in a modern text editor sometimes shows gibberish: the file is fine, the reader is just guessing a different encoding.
What the records actually contain
The data file is built from lines, each one a record of a particular type: a document header, a line item inside a document, a bookkeeping entry, a customer or supplier record, the reporting business's own details. Each record type has a fixed layout of fixed-width fields. That's why the file looks like a dense block of text with no obvious separators, and it's also why every program reads it identically.
When you need it
Three common situations call for it: a routine request from your accountant to prepare financial statements and the annual income tax return, a Tax Authority audit, in which the Tax Authority is entitled to request the file directly from the business, and switching between bookkeeping systems to carry your full history over to a new one without retyping everything.
There's a fourth, less discussed: checking yourself. Exporting the file and confirming it validates is a fast way to find problems in the books before your accountant finds them.
What happens without a valid Open Format file
A business that keeps its documents only as individual PDF files, with no system that can export Open Format, ends up having to manually re-enter dozens or hundreds of documents every time the file is needed. It's an expensive, error-prone process that an accountant will usually charge extra for.
In an audit the picture is worse. Failing to produce the file can lead to the books being rejected, and from there to an assessment that isn't based on what was actually reported. It's the same exposure described in the document retention guide, from a different angle.
The mistakes that fail validation
- A date range that doesn't match what was asked for, such as a partial tax year instead of a full one.
- Documents issued in another system and left out of the export, which makes the numbering look incomplete.
- A mismatch between document totals and entry totals, usually after a manual correction instead of a credit note.
- Missing business details in the file header, such as a dealer number never entered in settings.
Most of these aren't problems with the file. They're problems in the books, and the file is what exposes them.
What to do with the file once it's exported
The file is usually sent straight to your accountant, who imports it into their own system to prepare the reports. It is one item on the year-end document list. If the Tax Authority requests it directly, it's submitted to them according to whatever instructions they give. Either way, keep a copy of exactly what you sent, alongside the rest of your fiscal documents.
The file's second use is moving between systems. It is the only common denominator across every Israeli invoicing product, which makes it the bridge that carries history from one system to another. The right order, what moves and what stays, and what happens to numbering, are in the switching invoicing software guide.
When to run an export nobody asked for
An export is a cheap health check. The file is built from what is in the books, and any inconsistency between the two surfaces in validation rather than in an audit.
Three moments where it pays off: at the end of each quarter, to catch a problem while it is still small; in December, before closing the year, while there is time to fix things; and before any move between systems, to know exactly what is going to carry across.
What to check in a file you received from a previous system
Anyone importing history from another system is handed a file they did not produce, and it is worth opening before trusting it. Three checks: that the date range covers the whole trading period rather than a single year, that the business number in the header is really yours, and that the document totals square with what you remember from the periodic reports.
A partial file imported quietly is the worst problem in this category, because it looks like success.
How Slate produces Open Format
Slate produces a complete Open Format file (INI plus BKMVDATA) in a single click, straight from the documents already issued in the system, and also supports importing an Open Format file from a previous system. Moving to Slate doesn't require retyping your existing history, and imported documents are kept separate from the live numbering so the historical record never mixes with new documents. The documents the file describes are shown in the document samples.
This is general information, not tax advice. For a specific situation, talk to an accountant or tax adviser.
Common questions
What is an Open Format file?
A standard file format set by the Israel Tax Authority for transferring accounting data. It consists of an INI file describing the structure and a BKMVDATA file holding the data, both inside a single ZIP.
Who can demand an Open Format file from me?
Your accountant, for the annual financial statements, and the Tax Authority in an audit, directly from the business. It is also what carries history across when moving between bookkeeping systems.
Why does the file open as gibberish?
Because it is encoded in ISO-8859-8-I, a pre-UTF-8 Hebrew encoding kept in the standard for backward compatibility. The file is fine, the editor is simply guessing a different encoding.
What if my system cannot export Open Format?
The documents have to be re-entered into a system that can, which is expensive and error-prone. In an audit, failing to produce the file can lead to the books being disqualified and a best-judgment assessment.
What fails validation?
Usually a wrong date range, documents issued in another system and left out, a mismatch between document totals and journal entries, or missing business details in the header. Most problems are in the books, not the file.
Do I keep a copy after sending it?
Yes. Keep the file exactly as sent, alongside the rest of your fiscal documents, for seven years from the end of the tax year.