How do I open a BIR DAT file?

A BIR DAT file is a plain-text, comma-separated file — you can open it in any text editor, but the columns won't be labeled. This viewer parses it into a labeled table instead: upload the file, and it groups the lines into header, detail, and control records automatically.

Does this tool upload my DAT file anywhere?

No. The file is read and parsed entirely in your browser using the File API — it is never sent to a server. That also means closing or refreshing the page clears it; nothing is saved unless you're signed in to BIR Online Tools and generate the file there.

Can this viewer validate my DAT file for BIR submission?

No. This is a lightweight preview and totals-check tool, not a replacement for the official BIR Validation Module. Always validate the actual file with BIR's own module before eSubmission.

What DAT file formats does the viewer support?

It supports the comma-separated, quoted-field record format used by RELIEF, QAP, and SAWT DAT files, where each line starts with a record-type marker (an H, D, or C prefix) identifying it as a header, detail, or control record.

Free BIR DAT File Viewer — Open and Preview a .DAT File Online

Open a BIR DAT file and see it as a readable table instead of a wall of comma-separated text — entirely in your browser, nothing uploaded. Drop in a RELIEF, QAP, or SAWT .DAT file below to view its header, detail rows, and control-record totals.

Drop a .DAT file here, or click to choose one

Processed entirely in your browser — the file is never uploaded.

This is a preview tool, not the official BIR Validation Module. It groups your file's lines into header, detail, and control records and totals numeric detail columns so you can eyeball them against the control record. Always validate the actual file with BIR's own Validation Module before eSubmission.

What this tool does #

The BIR DAT file viewer reads a .DAT file’s lines and groups them by record type — a header record (filer TIN, branch code, return period), one detail record per payee or transaction, and a control record with column totals. It’s the same three-record-type structure BIR Online Tools’ own RELIEF, QAP, and SAWT generators produce: each line starts with a record marker (H, D, or C) followed by comma-separated fields, with text fields wrapped in quotes.

Everything happens in your browser using the File API — the file is read locally and never leaves your device, so it’s safe to preview a file with real client TINs and payroll data.

What it doesn’t do #

This viewer does not replace the official BIR Validation Module. It doesn’t check ATC codes against the current list, confirm TIN registration, or apply BIR’s own field-length and format rules — it only shows you the file’s structure and sums numeric detail columns so you can compare them against the control record before you run the real validation step.

BIR DAT File Validation Module — what the official module checks
BIR DAT File Naming Convention and Folder Structure
How to Convert Excel to a BIR DAT File

Ready to generate a BIR-ready DAT file instead of just viewing one? QAP · SAWT · RELIEF are free in BIR Online Tools.

What this tool does #

What it doesn’t do #

Related reading #