Assemble labelled filing attachments that pass the upload checks

Preparing a reply to a notice or an appeal submission is mostly substantive work, and then it runs aground on something entirely mechanical: a 9 MB scan against a 5 MB limit, at eleven at night, on the last day of the window.

This guide is about the mechanical part. The substance of what you file is a matter for your tax adviser, and nothing here is tax advice.

Size limits cause most failed submissions

Filing portals impose limits per attachment and often on the total submission. The numbers vary by portal and by form, and they change, so read the limit on the page you are submitting from rather than relying on what it was last year.

Then check your files against it before you start the submission, not while you are inside a session that may time out. The filing preparation tool assembles the attachment set, applies labels, builds an archive, and checks sizes, which turns the discovery of an oversized file into a preparation-time problem rather than a deadline-time one.

When a file is too large, work in this order:

1. Reduce the scan, not the content. Most oversized attachments are 600 dpi colour scans of black-and-white paper. Rescanning or recompressing at 300 dpi greyscale often cuts the size by three quarters with no loss of legibility. The compression tool handles this.
2. Split by document, so each attachment is one logical item rather than an omnibus file.
3. Remove pages that are not needed. Blank separator sheets, duplicate copies, and the reverse sides of single-sided documents add bulk and nothing else.
4. Only then consider reducing quality further, and check the result is still comfortably readable when printed.

Do not compress until text becomes marginal. An attachment a reviewer cannot read is worse than one that took two attempts to upload.

Label so a stranger can follow it

The person opening your attachments has not read your case file and has a queue of others. Names are the only navigation they have.

Good practice:

• Number for order. 01-reply-covering-letter.pdf, 02-annexure-a-invoices.pdf, 03-annexure-b-ledger.pdf. Zero-pad the numbers so they sort correctly.
• Name the content, not the source. annexure-c-bank-statement-apr-2026.pdf beats scan0043.pdf.
• Match the names to the references in your reply. If the reply cites Annexure B, the file should say Annexure B. Nothing wastes a reviewer's time like a cross-reference that does not resolve.
• Avoid special characters. Stick to letters, digits, hyphens, and underscores; some portals reject the rest.
• Keep names reasonably short. Long names combined with deep paths cause failures on some systems.

Where the portal accepts a single archive, bundle in that structure using the archive tool. The bundling guide covers naming inside an archive, which matters just as much as the archive name itself.

A pre-upload checklist

Run through this before opening the submission session:

• Every attachment opens, from beginning to end, in a plain reader.
• Every page is legible at 100 percent zoom, especially figures and stamps.
• Nothing is upside down or sideways.
• Page counts match what the reply says they are.
• Each file is under the stated per-file limit, with margin.
• The total is under any overall limit.
• File names are sequential and match the references in the reply.
• No file is password-protected — portals cannot open them and will reject the submission.
• No document carries annotations, comments, or highlights left over from internal review.
• Metadata does not carry internal author names, template titles, or file paths you would rather not disclose.

That last pair is worth genuine attention. Internal review comments and draft metadata inside a submitted attachment disclose your own working, which is not something you can retract after upload.

Keep an exact record of what you filed

After a successful submission, save a copy of the exact files you uploaded, in the exact order and with the exact names, alongside the acknowledgement. Not the working folder, and not the drafts — the submitted set.

Months later, when a query arrives, the question is always what was actually filed. Being able to answer that precisely, with the same files a reviewer is looking at, is worth the two minutes it takes to save them properly.

Finally: these documents are the most sensitive an assessment produces, containing ledgers, statements, and correspondence. Assembling and compressing them in the browser means they are never handed to a third-party service on the way to being filed.