Convert and Edit PDF Files: Converting, Scanning, Signing and Redacting

Why Business Documents End Up as PDFs

Most documents a Hong Kong company produces end up as a PDF at some point. Board minutes are circulated as PDFs, audited accounts go to the bank as a PDF, signed forms are scanned into PDFs, and many government and licensing portals accept supporting documents in that format. Knowing how to convert and edit PDF files properly is therefore an administrative skill rather than a technical one, and most of the problems people run into come from choosing the wrong method rather than the wrong tool.

This guide covers the three jobs that make up nearly all PDF work: converting a document to PDF, converting from PDF back into something editable, and changing a PDF that already exists. It also covers the tasks around them, such as scanning, merging, compressing, signing and redacting, and the two points where getting it wrong has consequences beyond a messy file: removing personal data, and signing documents electronically.

Where this guide names an online tool, it uses PDFBEAR as the example, because it covers every task below in one place and runs in a browser. The limits quoted for it were taken from its own pricing page at the time of writing and may change.

Convert to PDF: Word, Excel, PowerPoint and Images

The simplest way to convert to PDF is usually the software you already have. Microsoft Word, Excel and PowerPoint can all save or export a document as a PDF directly. On a Mac, any application that can print can also save as PDF from the print dialog, and Windows includes a "Microsoft Print to PDF" printer that does the same thing.

An online Word to PDF, Excel to PDF or JPG to PDF converter is useful when you are on a machine without the original software, or when you have a batch of photographs of receipts to turn into one document.

Whichever route you take, check three things before you send the file:

• Fonts. A PDF should embed its fonts, so it looks the same on the recipient's screen. Office exports do this by default. If Chinese characters appear as boxes or blanks, the font was not embedded.
• Page size. Hong Kong uses A4. A document set up in US Letter prints with odd margins and can be cut off on a Registry or bank form.
• What Excel actually prints. Excel to PDF converts the print area, not what is on your screen. Hidden columns, a print area set months ago, or a sheet that spills over several pages all come through as they would on paper.

Scan to PDF: Signed Forms and Paper Records

Scanning is how a wet-ink signature becomes a file. The Companies Registry's electronic services, like many licensing portals, accept scanned copies of signed forms and supporting documents, so the quality of the scan matters.

You do not need a dedicated scanner. The Notes app on an iPhone has a document scanner, Google Drive's mobile app can scan to PDF, and most office multifunction printers can scan straight to email. A few habits make scans much easier to work with:

• Scan at a resolution that keeps small print legible. 300 dpi is a sensible default for text documents.
• Use greyscale or black and white for text. Colour scans of plain documents are several times larger for no benefit.
• Keep one document per file, and name it by what it is and when it was signed, not "Scan_0042.pdf".
• Check every page is present and the right way up before the originals go back in the file.

A scanned page is a picture of text, not text. That matters as soon as you want to search it, copy from it or convert it to Word, which is what OCR is for.

Convert from PDF: Word, Excel and Images

Converting from PDF is the reverse journey, and it is less reliable, because a PDF records where things sit on a page rather than what they are. A converter has to guess which lines form a paragraph, which cells form a table and which text is a heading.

• PDF to Word is the common case: a contract received as a PDF that needs amending, or an old policy whose source file is lost. Simple documents convert well. Multi-column layouts, footnotes and tables are where the output needs checking line by line.
• PDF to Excel is useful for bank statements and financial schedules. Always check the totals after conversion. A misread digit or a merged cell is easy to miss and expensive to rely on.
• PDF to JPG turns each page into an image, which is what you want for a slide, a social post or a portal that only accepts images.

Treat any converted document as a draft. Read it against the original before it replaces the original anywhere.

OCR PDF: Making a Scanned PDF Searchable

Optical character recognition (OCR) reads the shapes on a scanned page and adds a real text layer underneath. After OCR, a scanned PDF can be searched, copied from and converted to Word with usable results. Without it, a PDF to Word conversion of a scan gives you a Word file containing pictures.

OCR accuracy depends on the scan. Clean, straight, high-contrast pages come through well. Faint photocopies, handwriting, stamps across text and mixed Chinese and English on the same line all produce errors, so check names, figures and dates in the output. On PDFBEAR, OCR PDF is a paid Premium feature rather than part of the free tier.

How to Edit a PDF, and What "Editing" Really Means

"Edit a PDF" covers two very different things, and most frustration comes from mixing them up.

Adding to a PDF works well in any editor. Text boxes, highlights, comments, shapes, images, page numbers and signatures sit on top of the existing page. This is the right approach for annotating a draft or filling a form that has no fields.

Changing the existing text is harder than it looks, because the PDF format was built for final documents. Many online editors, PDFBEAR's included, handle it by covering the old words with a white box and placing new text on top. The page looks corrected, but the original text is still in the file underneath, and anyone who copies the text or removes the box can read it.

So the reliable way to change the content of a document is to change its source. If you have the Word or Excel original, edit that and export a fresh PDF. If you do not, convert PDF to Word, make the changes, check the layout, and convert the result back to PDF.

One firm rule: a document that has been signed, filed or sent to a counterparty should not be edited at all. Produce a new version, sign it again if it needs signing, and keep both.

Merge, Split and Compress PDF Files

Filings and applications usually ask for a set of documents rather than one. Merge PDF files into a single document in the order the application lists them, and a reviewer can work through it without hunting.

Split a PDF when one scan contains several documents, or when a portal wants each attachment separately. Deleting or reordering pages is the same operation in a different form.

Compress PDF files when an upload is rejected for size. Portals set their own limits, and a scanned document in colour is the usual cause of an oversized file. Compression mostly works by reducing image resolution, so open the result and check the small print is still readable before you submit it.

Fill PDF Forms and Sign a PDF

A fillable PDF has form fields you can type into, and some statutory forms are published that way. Where a form has no fields, an editor's text tool lets you type over the blank spaces instead. Either way, download a statutory form fresh from the body that issues it each time you use it. The Companies Registry revises its specified forms, and an old copy saved on a shared drive is a common reason for a rejected filing.

To sign a PDF electronically, you can draw, type or upload a signature image and place it on the page. In Hong Kong, the Electronic Transactions Ordinance (Cap. 553) gives electronic records and electronic signatures legal recognition in most commercial settings. It does not cover everything. Schedule 1 to the Ordinance excludes certain documents, including wills, trusts, powers of attorney, oaths and affidavits, statutory declarations, negotiable instruments, deeds and conveyances dealing with land, and any instrument that must be stamped under the Stamp Duty Ordinance (Cap. 117). That last category catches instruments of transfer for shares in a Hong Kong company, which is easy to overlook. For those, and for anything where the other party or a regulator requires a wet-ink original, sign on paper.

A company should also check its articles of association before relying on electronic signatures for board resolutions, and keep a record of how and when each document was signed.

Protect, Unlock and Redact a PDF

Protecting a PDF with a password is worth doing before sending anything containing identity documents, payroll details or bank information by email. Send the password by a different channel, such as a phone message, so that one intercepted email does not expose both.

Unlocking a PDF removes a password or restrictions from a file. Only do it for files you are entitled to open, typically your own documents whose password has been lost.

Redacting a PDF is where mistakes are most costly. Drawing a black rectangle over a name hides it on screen but, as with the white-box method of editing, it leaves the text in the file. Proper redaction removes the underlying content. After redacting, test the result: search the PDF for the redacted word and try copying text from the redacted area. If either works, the redaction failed.

Under the Personal Data (Privacy) Ordinance (Cap. 486), a data user must take practicable steps to protect personal data against unauthorised or accidental access. A copy of a Hong Kong Identity Card sent out with a black box drawn over it, but the number still in the file, is exactly the kind of lapse that principle is aimed at.

PDF/A for Records You Must Keep

PDF/A is a version of PDF designed for long-term archiving, standardised as ISO 19005. It requires everything needed to display the document, including fonts, to be embedded in the file, and it forbids features that depend on anything outside the file. A PDF/A document should open and look the same in twenty years.

That is relevant because retention periods are long. A company must keep its accounting records for seven years under the Companies Ordinance (Cap. 622). When you convert to PDF/A for the archive, keep the original too until you have checked the converted copy.

Online PDF Tools and Confidential Documents

Using an online PDF converter means uploading your document to someone else's server. For a price list or a brochure that does not matter. For payroll, identity documents, client files or anything under a confidentiality obligation, it is a decision worth making deliberately.

Check what the service says about retention and security before you upload. PDFBEAR's pages state that uploads travel over HTTPS and are automatically deleted from its servers shortly after processing. For the most sensitive material, the export and print-to-PDF features built into Office, macOS and Windows keep the file on your own machine throughout.

Convert and Edit PDF Files: Which Tool for Which Job

PDFBEAR's free account allows unlimited conversions of up to 30 pages or images each, with files up to 50 MB. Without an account, the limit is five conversions a day of up to 10 pages each. OCR, batch processing and its AI tools are part of the paid Premium plan.

Getting It Right

Most PDF problems in an office come from treating the PDF as the working document. Keep the source file as the master, convert to PDF when a document is final, and treat anything converted back from a PDF as a draft to be checked. Scan cleanly, compress only as far as legibility allows, redact properly rather than cosmetically, and never alter a document after it has been signed.