Working at the post office in Cat Mail Co. is a charming experience, but if you want more than just the satisfaction of helping humanoid cats, you will want to hunt down every achievement. Most of these are straightforward, though some require specific room unlocks or item interactions.

Cat Mail Co. Achievement List

Here is how you can earn every achievement available in the game:

AchievementRequirement
Heave HoUse the scanner to identify a heavy parcel and attach the weight sticker.
Iced WhiskersUnlock the refrigerator room key by the counter and open the side hallway fridge room.
Be CarefulScan a parcel, identify the glass icon, and apply the fragile glass sticker.
Cats Don't Belong In WaterJump into the water located at the back of the post office.
Keep It ColdScan a parcel for the snowflake icon and apply the ice temperature sticker.
From Cats Island With LoveApply one decorative stamp to any parcel via the sticker menu.
Until Shipment Do Us PartScan a 'lovers' package (marked with a heart) and stamp it with a heart.
Night Vision ActivatedPlay until you gain access to the dark room, then enter it.
Float Mail Co.Load 30 or more parcels onto the boat when it arrives (using smaller parcels makes this easier).
Stamps HobbyistPlace 10 stamps on a single parcel.
As Good As NewRepair a damaged (dark/rough-looking) parcel at the bench in the repair room.
Take Off Your FurrProgress through the game until you unlock the heated room.
Hot, Hot, Hot!Scan a parcel needing heat and apply the hot sticker.
Heavy DutyApply a total of 500 regular or decorative stamps across all parcels.
Sunbath SiestaUnlock the light room by playing through the game, then enter it.
A Well Deserved RetirementComplete the story and liberate the old postman.
All cleaned upEmpty the entire pile of packages in the main room.

Tips for Completion

For achievements like Heavy Duty, you simply need to keep applying stamps to every parcel you process. Don't worry about wasting them; as long as you hit the 500-stamp threshold, the achievement will unlock.

For All cleaned up, note that not every package in the main room's pile is available immediately. You will need to progress through your shifts to make them all accessible, so this achievement will naturally come toward the end of your playthrough as you finish the story and earn A Well Deserved Retirement.