# Activate your Scalpel licence > Find your licence key, paste it into Scalpel's licence screen and start trading. How the two-computer limit, 12-hour check and 72-hour offline grace work. Source: https://scalpeltrade.com/guides/activate-licence Guide 1.3, Getting started. Beginner, 5 min read. Checked with Scalpel 1.12.8 on 2026-10-15. By Scalpel Team. **In short:** Your licence key looks like **SCLP-XXXX-XXXX-XXXX-XXXX**. It is on your account page at scalpeltrade.com and in your purchase email. The first time Scalpel opens it shows the licence screen: paste the key, click **Activate**, and the cockpit opens. One licence covers two computers; Scalpel checks it at every start and every 12 hours, and keeps working for up to 72 hours if it cannot reach scalpeltrade.com. Scalpel is a one-off purchase: one payment, a lifetime licence, two computers, every update. There is no trial mode, so the licence screen is the first thing a new install shows. It takes about a minute. **Before you start:** - Scalpel installed ([guide 1.1](https://scalpeltrade.com/guides/install-scalpel-windows) for Windows, [guide 1.2](https://scalpeltrade.com/guides/install-scalpel-mac) for a Mac). - An internet connection for the first activation. - A licence. No licence yet? The licence screen's **Buy a licence** button takes you to the pricing page. Every purchase has a 7-day refund ([guide 12.4](https://scalpeltrade.com/guides/refunds-and-billing)). ## Activate Scalpel ### 1. Copy your key from your account page Sign in at [scalpeltrade.com/account](https://scalpeltrade.com/account) with the email you bought with (Scalpel sends you a sign-in link; there is no password). Your key is in the **Lifetime licence** panel. Click **Copy key**. The same key is in the email you got when you paid. *Screenshot: Simplified. The licence panel on your account page: the key, Copy key, and the machines using it. Machines 0 of 2 means it has not been activated anywhere yet.* ### 2. Paste it into the licence screen Open Scalpel. After the splash you see **Activate Scalpel**. Click the key box (1) and paste with `Ctrl`+`V` (`Cmd`+`V` on a Mac). You do not have to be exact: spaces are dropped, upper and lower case are the same, and the letters O, I and L are read as 0, 1 and 1, the characters keys use instead. *Screenshot: The licence screen: the key box (1), Activate (2), Find my key (3) (opens your account page), Buy a licence (4), and this computer's name (5).* ### 3. Click Activate Click **Activate** (2) or press `Enter`. The button reads **Checking...** while Scalpel asks scalpeltrade.com, then the cockpit opens. Scalpel saves the key, so you never type it again on this computer. ### 4. Check it in Settings Open **Settings** (`Ctrl`+`,`) and the **About** tab. Under **Licence** you see **Licensed** with your key masked to its last four characters, such as `SCLP-****-****-****-W8RB`, and how many of your two computers are in use. **Manage licence and computers** opens your account page. Back on the account page, the computer now appears under **Machines 1 of 2** with the name from the licence screen (5), when it was last seen, and the Scalpel version it runs. ## Two computers per licence A licence is for one trader on two computers: a desktop and a laptop, or a Windows PC and a Mac. Each computer is recognised by a private fingerprint of its system ID; Scalpel never sends your files or your trading to the licence server, only the key, that fingerprint, the computer's name and the app version. To use Scalpel on a third computer, free one first: on your account page, click **Free this machine** next to the one you no longer use, then activate the new one. You can free up to three computers in any 30 days; ask in Discord if you need more. Step by step: [guide 12.1](https://scalpeltrade.com/guides/move-licence-new-computer). **Note.** Reinstalling Scalpel, moving the app or updating it does not use a new slot. The slot belongs to the computer, so the same machine always activates into the slot it already has. ## The 12-hour check and the 72-hour offline grace Scalpel checks the licence when it starts (the launch screen stays on the Scalpel logo with "Checking your licence" until it answers, about 10 seconds at most if scalpeltrade.com cannot be reached) and every 12 hours while it runs. Each good check gives this computer a signed pass that is valid for 72 hours without the internet. So: - **Your internet drops, or scalpeltrade.com is down:** nothing happens. Scalpel runs on its last pass, and **Settings > About** says **checked offline** and how long is left. - **Scalpel cannot check in for more than 72 hours:** the next time it starts, it asks you to connect. It never locks you out in the middle of a session. *Screenshot: Settings, About during the offline grace: Scalpel has not reached scalpeltrade.com recently and says how long it can keep running without it.* ## A licence problem never traps you in a trade If a check fails while you trade (the licence was refunded, say, or the offline period ran out), Scalpel shows a banner under the header that says so and **keeps running until you quit**. Your positions, orders and app-monitored stops carry on as normal. If the licence screen ever appears at start-up while you still hold something (a position left over in your IBKR account, for example), it shows what is open and a red **Flatten all** button that closes everything at the market. Your stops are still being watched in the meantime. *Screenshot: The licence screen with a position still open: the stops are still watched, and Flatten all closes everything.* ## What the licence screen can say | Message | What it means | What to do | |---|---|---| | That licence key was not found. Check it on scalpeltrade.com/account. | A typo, or a key from somewhere else | Copy the key from your account page again | | That licence key is not in the right format. | Characters are missing | Paste the whole key, starting SCLP | | This licence is already active on 2 machines. Free one at scalpeltrade.com/account. | Both slots are taken | Free one on your account page, then click **Try again** ([guide 13.8](https://scalpeltrade.com/guides/fix-licence-machine-limit)) | | Scalpel can't reach scalpeltrade.com to check your licence. Check your connection and try again. | No internet on the very first activation | Get online and click **Try again** ([guide 13.9](https://scalpeltrade.com/guides/fix-licence-offline)) | | This licence is no longer active (refunded or disputed). | The purchase was refunded or charged back | Buy again, or contact support if this is a mistake | *Screenshot: Refused for the machine limit. Free a computer on your account page, then click Try again: the key you pasted is kept.* ## Questions **Where do I find my Scalpel licence key?** On your account page at scalpeltrade.com/account, in the Lifetime licence panel, with a Copy key button. It is also in your purchase email. The licence screen's Find my key button opens the account page. **Is there a free trial?** No. Scalpel needs a licence key to open. Every purchase has a 7-day refund instead, and the whole app, SIM included, is yours from the first minute. **How many computers can I use Scalpel on?** Two at a time, Windows or Mac in any mix. Free one on your account page to move the licence to another computer; you can free up to three in any 30 days. **Does Scalpel need the internet to run?** It needs to reach scalpeltrade.com to activate and then at least once every 72 hours. Between checks it runs offline on its last check. It always needs your TWS or IB Gateway connection for market data. **What happens if my licence check fails in the middle of a trade?** Nothing changes until you quit. Scalpel shows a banner and keeps running, your stops keep being watched, and it asks for the licence again at the next start.