FillOnce guide
Privacy-first PDF form filling with BYOK encryption
FillOnce fills structured PDF, Word, and spreadsheet forms from a vault encrypted with your key (BYOK). Matched fields appear for review; FillOnce never auto-submits and does not send vault values to third-party AI.
What “privacy-first form fill” means here
Privacy-first means your reusable answers stay under your encryption key, fills happen with a review gate, and marketing AI never trains on vault contents.
That is different from cloud PDF editors that keep editable copies on their servers for convenience.
Supported structured forms (honest scope)
Today: fillable PDF → filled or flat PDF / CSV; DOCX → filled DOCX / CSV; XLSX → filled XLSX / CSV; import filled DOCX into the vault.
Export (same document family) and conversion (change representation, e.g. XLSX↔CSV) are separate capabilities. Conversions require a paid plan.
How to fill a PDF without shipping data to an AI vendor
1. Create a person profile and save answers (or import from a form you already filled).
2. Upload a blank fillable PDF.
3. Review suggested mappings, export, then submit the form yourself on the destination site or portal.
Related intents: privacy PDF form autofill · BYOK encrypted form filler · client side PDF form fill. Scope stays limited to structured forms and supported file conversions.