What is an LPA string?
LPA:1$... is what an eSIM QR code actually contains. Here is how to read the three parts, when to type it by hand, and why it usually works only once.
If a provider has ever sent you something that looks like this:
LPA:1$smdp.example.com$K2-4HJ9-QX7R
that is an activation code, and it is exactly what the QR code on your eSIM contains. Scanning the code and typing this line do the same thing. The QR is just a way to avoid typing it.
What LPA stands for
LPA is the Local Profile Assistant: the piece of software inside your phone whose job is downloading and installing eSIM profiles. It is part of iOS and Android, not something you install.
So the string is addressed to that component. It says: here is where to go and what to ask for.
The three parts
The format is defined by the GSMA, the body that writes the eSIM standards, so it is the same on every phone and from every provider.
LPA:1is the header. The 1 is the format version.smdp.example.comis the address of the SM-DP+, the server holding your profile. It is a normal domain name, and it belongs to whoever produced the eSIM, which may not be the company you bought from.K2-4HJ9-QX7Ris the matching ID: the single reference that tells that server which profile is yours.
Sometimes a fourth field follows, a flag meaning a confirmation code is required. In that case your provider gives you a separate short code to type during installation.
When to type it instead of scanning
Three cases where the manual route is the better one:
- The QR code is on the screen you are installing from. You cannot scan a code with the same phone that is displaying it, so paste the string instead.
- The camera will not read it. A screenshot that has been forwarded through two chat apps is often too compressed.
- You are installing on a phone with a broken camera.
On iPhone: Settings, Cellular, Add eSIM, then look for the option to enter details manually. On Android the wording varies, but there is always a manual entry path next to the scanner.
Why it usually works only once
A matching ID normally refers to one profile and one installation. Once the SM-DP+ has handed that profile over, the code is spent. Scan it again and you get an error saying the code is no longer valid, which is working as designed rather than a fault.
This is the reason deleting an eSIM is close to permanent, and the reason an activation code is worth treating as a private thing. Anyone who gets the string before you use it can install your eSIM on their phone.
Quick answers
Is an LPA string the same as a QR code?
Yes, in content. The QR code is a picture of the string. Scanning it and typing it do the same thing.
Can I reuse my activation code on a second phone?
Normally no. The code is good for one installation, and after that the server refuses it. Moving an eSIM between phones needs a transfer or a reissue from the provider.
What is the smdp part of the string?
The address of the server that holds your profile, run by whoever produced the eSIM. Your phone connects to it directly to download the profile.
I get "this code is no longer valid". What happened?
Almost always that the profile has already been installed once, either on this phone or another one. Check your eSIM list in Settings before asking for a new code, because it may already be there.