Password-protect the document and distinguish access from locking in Apple Numbers

Quick answer: Use File → Set Password to require a password for opening a local spreadsheet you own. The document’s Locked checkbox and Arrange → Lock only prevent accidental changes; neither substitutes for a document password.

A document password and a lock serve different purposes. This defensive exercise concerns only a local, disposable spreadsheet you own. You perform all password entry yourself. No example password is supplied, collected, saved, or tested by this tutorial, and no account, sharing, Keychain, or Touch ID settings need to be changed.

Understand the three controls

• A document password controls opening the file. Apple states that adding one encrypts the spreadsheet; this article does not test or certify encryption strength.
• The document’s Locked checkbox helps prevent accidental edits or file changes. Anyone can unlock that lock.
• Arrange → Lock protects a selected object from accidental modification until it is unlocked. It is not an access-control boundary.

A password does not retract a copy that already exists. Apple also notes that a new or changed password applies to that version and later versions. This local exercise is deliberately not a procedure for securing a shared document’s history, managing collaborators, or removing existing unprotected copies.

Create a harmless private test file

Create a Blank spreadsheet in Numbers on Mac. On Sheet 1, use Table 1 with three rows and two columns, one header row and no footer rows. Enter A1:B3:

Item	Units
Paper	3
Pens	5

The fixture has two records and eight units. Use no real confidential information. Save it as access-practice-before.numbers in a local Numbers Practice folder you control, not a shared folder. Use File → Save As to create access-practice-protected.numbers there. Check the filename at the top of the window before proceeding. The unprotected “before” copy remains harmless because this fixture contains no secrets.

Apply a password yourself

1. Keep access-practice-protected.numbers active. Choose File → Set Password.
2. Privately choose and enter a unique password and the requested confirmation. Do not paste it into a chat, screenshot, tutorial note, or fixture. Any hint should not reveal the password. Cancel if you are not ready to manage the password safely.
3. Leave optional password-remembering or Touch ID choices unselected for this practice when offered. Do not alter system settings or remove existing credentials to force a particular prompt. Click Set Password yourself only when you intend to protect this copy.
4. Save the file and close it. Reopen that exact protected file. If prompted, enter your password yourself. If an existing authorized unlock method opens it automatically, that alone does not prove a password was absent or bypassed.

Apple warns that a forgotten password cannot be recovered. Arrange secure password management before using this feature with important data. This exercise does not ask you to store the secret anywhere new, and provides no recovery bypass.

Check content and make a normal edit

Once you have opened your protected practice copy, verify Paper=3 and Pens=5. Change B3 to 6. The new total is nine. Increase the table to four rows and enter Clips and 2 in A4:B4; the total becomes eleven. These visible facts establish which copy you edited without putting a secret into a check log.

Save the completed access-practice-protected.numbers in Numbers Practice, close and reopen it, and check all three records. Do not assume password protection prevents legitimate editing after opening. Record only that your private verification was completed, not the password, hint, screenshots of credential fields, or a cryptographic test result.

Contrast a lock without confusing the result

For a separate lock demonstration, close the protected file and reopen the original access-practice-before.numbers. Use File → Save As to create access-practice-lock-demo.numbers. Confirm it still contains Paper=3 and Pens=5. Click the document name at the top, select Locked, then click outside the panel. Return to the same panel and clear Locked when you want to edit again. This checkbox is reversible without knowing the protected copy’s password; it is a different control on a different file.

For object locking, select Table 1 as an object rather than a cell and choose Arrange → Lock, then Arrange → Unlock. Keep this experiment in the lock-demo file. The protected deliverable remains separate.

Change, remove, or reset only intentionally

If you later want to change the password on a file you own, open it and use File → Change Password, entering the requested information privately. Removal uses the same dialog and Remove Password after entering the old password. Removing protection is an intentional security change, not a troubleshooting shortcut.

For optional data reset, reopen the protected file, choose File → Save As, and save a separate access-practice-reset.numbers copy in Numbers Practice. Confirm that access-practice-reset.numbers is the active filename at the top of the window before making any reset edits. Verify protection on that new copy yourself before relying on it. In the reset copy restore Pens to 5 and remove Clips so the source again totals eight. Keep the final protected file unchanged. Do not depend on Undo across reopenings.

If you forgot the password, use an already available authorized copy or your own established recovery resources; this tutorial cannot recover it. If Set Password is not the menu item you see, verify that you have the intended file and whether Change Password is present. Do not remove protection to make menu labels match. A successful local reopen check is not proof that every old copy, export, or shared version is protected.

For a row-removal step in a reset copy, point to that row’s number, click its menu arrow, and choose the delete-row command. Check the row’s label or values before deleting it. Header/footer counts are set with the Headers & Footer pop-up menus on Format → Table.

Scope and verification

Numbers 15.4 for Mac; documentation-qualified desktop workflow. Numbers on iPad, iPhone, and iCloud are not covered by these controls or checks. Apple’s cited guide identifies version 15.4; check Numbers → About Numbers on your Mac. This article was checked against first-party documentation on 2026-10-19. No native Mac application was available for execution, so the steps, save/reopen outcomes, and accessibility behavior remain untested in the application. No native screenshots are supplied; generated diagrams or website screenshots would not prove product behavior.

Official sources

• Welcome
• Password
• Lock
• Arrange
• Save
• Rows and headers

Related tutorial

See Protect formula tables while keeping inputs editable for the related workflow.