The Filing Cabinet is Books' built-in document storage — receipts, invoices, contracts, tax documents. Every attachment uploaded to a transaction also appears in the Filing Cabinet, plus you can upload standalone documents that aren't tied to a transaction.
What to Store
Receipts for expenses (especially anything you might need for an audit)
Invoices you issued to clients
Vendor contracts and engagement letters
Tax documents (1099s received, W-9s collected, prior-year returns)
Bank statements (if you want to keep them with your books)
Insurance policies, business registration documents
Uploading
From a transaction — open the transaction, drag a file onto the attachments area
Direct upload — go to Filing Cabinet → Upload and drag files in. You can tag them with a category and optional payee.
Email-to-file — every Books account has a unique upload email (look in Filing Cabinet settings). Email receipts directly to that address; they appear in your Filing Cabinet automatically.
Organizing
Documents can be:
Tagged with categories (Receipt, Invoice, Contract, Tax, etc.)
Linked to a payee for filtering ("show me all Comcast documents")
Linked to a transaction for cross-reference
Folders — create folders for any organization scheme you like
Searching
Search by filename, by tag, by payee, or by transaction. Books also performs OCR on uploaded images and PDFs, so you can search by text inside the documents — useful for finding "that one Amazon receipt for the printer" without remembering when.
Retention & Backup
Documents are stored encrypted at rest. Free plan: 100 MB. Growth: 1 GB. Pro: 10 GB. When you cancel your subscription, you can export all documents (one ZIP per folder) for 90 days, then they're permanently deleted.
Sharing Documents
Each document has a Share button that generates a unique time-limited URL — useful for emailing a vendor a copy of their invoice, or sharing a year of receipts with your accountant. Share links expire after 7 days by default (configurable).