Codes in Call of Duty are a single-player convenience with strings attached, and the strings are the part people skip.

Short answer

Enter them exactly as written, on the platform-appropriate input, and expect achievements to be disabled for that save.

Achievement locking is usually per-save rather than per-account, but not always. Anything that requires downloading a program is not a cheat code. If you are coming to this after a long break, the terminology has probably moved on.

Codes that no longer work

Some effects stack in ways the developers did not intend and the game does not handle gracefully. Case and spacing matter more than the lists suggest. Everything below is framed around the current state of Call of Duty rather than a launch-week impression. A code that softlocks a mission is a known risk in more than one of these games.

Codes typically do not persist through a reload, which surprises people who use them for convenience. There is no hidden trick here that the game is keeping from you. Console entry uses button sequences with tight timing, and mistiming reads as a broken code.

Anything promising online effects

Call of Duty is not shy about hiding useful information two menus deep, so some of this is simply knowing where to look. Where two approaches both work, the one with fewer moving parts is the one to keep. Anything that behaves differently on console than on PC is flagged where it matters.

  • Ignore any list that asks you to install something first.
  • Re-enter the same code to toggle an effect off.
  • Expect one number in every guide to be out of date; the method is what matters.
  • Save manually before using anything irreversible.
  • Never enter anything into an online mode.
  • If a menu path does not exist for you, your build is older or newer than the one described.

What you give up

The developers have changed their mind about this at least once, which explains the older advice. The short version is near the top on purpose; the reasoning is there if you want to know why. What follows assumes you are on a current install and have not modified it. Most of the disagreement you will find online is two people describing different builds.

Do the cheap check before the expensive one — that ordering alone saves most of the frustration. Half the pages on this topic were written for a build that no longer exists, which is why they stop matching what you see. Nothing here assumes a particular playstyle beyond wanting the thing to work.

How to enter them

The community wisdom on this is roughly half right, and the half that is wrong costs the most time. Screenshots age faster than text, which is why this describes rather than shows. There is usually a fast way and a reliable way, and it is worth knowing which one you are choosing.

The awkward part is rarely the step itself, it is knowing which step comes first. It helps to understand why a step exists, because then you can adapt it when your situation is slightly different. Patch notes move numbers around constantly; the shape of the answer holds even when a specific value shifts.

What each one actually does

Where something depends on your platform or region, that is called out rather than glossed over. A single check up front replaces a lot of guessing later. Treat anything stated without a version number as provisional.

Where people go wrong

  • Ignoring the platform-specific note and then wondering why the steps do not line up.
  • Assuming a guide from an older season still describes the current version.
  • Trusting a video thumbnail that promises a result the video never actually shows.

Call of Duty FAQ

Do achievements still unlock?

Generally no, for the save you used them on. Starting a clean save restores normal unlocking.

How long does this take?

Minutes if it goes cleanly, an evening if you hit the edge case in the caveats list. Neither is unusual.

What if none of this works for me?

Then something in your setup differs from the assumption — version, region or platform. Check those three before anything else.

Will using these get me banned?

Not in single-player, where they are an intended feature. Anything claiming to do the same online will absolutely get an account banned.

Anything that shifts with the next Call of Duty update will show up as a changed number, not a changed approach.