> ## Documentation Index
> Fetch the complete documentation index at: https://docs2.travtus.com/llms.txt
> Use this file to discover all available pages before exploring further.

# File Requirements & Validation

> Rules and pre-flight checks for File Uploads

## File Requirements & Validation

* **Supported formats:** csv (UTF-8), json (UTF-8), json.gz (UTF-8). Gzipped CSV (`.csv.gz`) is not supported.
* **S3 key shape:** `companyName_companyId/TYPE-SUBTYPE/filename.ext`.
* **CSV specifics:** Header row required. Delimiter must match the mapping config (`delimiter`); if none is set, it defaults to a comma (`,`). Fields should not span multiple lines.
* **Encoding:** UTF-8 only; no BOM(Byte Order Mark). (Header BOM is stripped if present, but avoid it.)
* **Nulls & placeholders:** Use empty cells for nulls. Reject/clean `NULL`, `N/A`, `-`, or whitespace-only placeholders.
* **Schema expectations:** A mapping config must exist for `company_id + file_type-subtype` (defaults for community/user/resident/agent). Columns
  must match configured headers [Data structure](./data-types-and-data-structure/community); extra/missing columns fail mapping. Portfolio ID must be present or derivable for non-default types.
* **Validation consistency:** Column count must stay constant per row; use consistent line endings (`\n` or `\r\n`). No control characters or embedded
  binaries/base64 blobs.

## Pre-flight Checklist for Uploaders

* [ ] File extension is `.csv`, `.json`, or `.json.gz`
* [ ] UTF-8 encoding, no BOM
* [ ] Delimiter matches mapping config (or default comma if not configured)
* [ ] Nulls are empty cells (no `NULL`/`N/A`/`-`)
* [ ] Headers match the expected mapping; column count is consistent
* [ ] S3 key follows `companyName_companyId/TYPE-SUBTYPE/filename.ext`