If you have researched digital membership cards, you have met the word: .pkpass. It appears in vendor comparisons, developer documentation, and the occasional email attachment that opened, as if by magic, straight into Apple Wallet.
This is a plain-language explanation of what a pkpass actually is, how it gets onto a member's iPhone, how it updates afterwards, and what all of it means for an organisation deciding between building and buying. No code, no jargon left undefined.
A pkpass is a signed folder
Strip away the mystery and a .pkpass file is a compressed folder with three kinds of content:
- A description of the pass: the fields and values, such as member name, ID, tier, and expiry date, plus colours and layout choices, written in a structured text format
- The images: your logo and any artwork, supplied at the sizes Apple specifies
- A digital signature that proves the pass was created by a registered issuer and has not been tampered with
The signature is the important part. iPhones refuse passes that are not correctly signed, which is why members can trust that a card claiming to be from your club really is. It is also why you cannot simply export a pretty image and call it a wallet pass.
How the pass reaches the phone
The member taps an Add to Apple Wallet link or button, in an email, on a web page, or behind a QR code. The phone downloads the pkpass, checks the signature, and files it in the Wallet app. That is the entire ceremony: no app store, no account, no login.
For membership cards, the pass type used is Apple's generic card layout rather than the boarding pass or event ticket layouts, which is why a well-made membership pass shows identity fields and a scannable code rather than gates and seat numbers.
How the card updates after it is issued
This is the piece that separates wallet passes from a PDF or an image. When a phone adds a pass, it quietly registers with the issuer's update service. From then on:
- Your organisation changes something, say a renewal extends the expiry date
- The issuer's service tells Apple something changed
- The phone fetches the fresh pass in the background
The member does nothing, and the card in their wallet is simply correct the next time they look. This is how a membership card can show live expiry and status for years without ever being re-sent, and it is the machinery behind what our renewal software does to cards automatically when a member pays.
What Google Wallet does instead
Android's equivalent skips the signed file. Google Wallet passes are created and updated through Google's issuer API: your card platform tells Google what the pass contains, and Google renders it in the Wallet app on the member's phone. Different plumbing, same member experience: one tap to add, automatic updates, offline access to the code.
The practical differences between the two platforms are small and mostly invisible when both are issued from one design; our Apple Wallet vs Google Wallet comparison covers them in full.
What this means if you are deciding between building and buying
Knowing what a pkpass is makes the build-versus-buy question concrete. To issue and maintain membership passes yourself, your organisation would need:
- An Apple Developer account, a registered pass type identifier, and a signing certificate that expires and must be renewed without breaking every issued pass
- A pass update web service that runs permanently, because updates are what make the card worth having
- The Google Wallet issuer account and API integration for the Android half of your membership
- Ongoing maintenance for all of it, forever
None of this is beyond a software team, which is exactly the point: it is a software team's job, not a membership manager's. A card platform such as Memberlytic's digital membership cards runs this machinery as a service, so your involvement is the member list and the branding. You can start from a simple export, as covered in creating digital membership cards from a spreadsheet, and never think about certificates at all.
Frequently Asked Questions
What is a .pkpass file in simple terms?
It is a signed, compressed folder containing a pass description, images, and a digital signature. iPhones open it directly into Apple Wallet, where it becomes a card that can display fields such as member name, tier, and expiry, plus a scannable code.
Can we make a pkpass ourselves without a developer?
Not practically. Passes must be signed with a certificate tied to an Apple Developer account, and useful membership cards also need an update service so expiry and status stay current. A card platform handles the signing, hosting, and updates, and takes a member list as its only input.
Why does my membership card update by itself in Apple Wallet?
When the pass is added, the phone registers with the issuer's update service. When your organisation changes the record, the service notifies Apple and the phone fetches the fresh pass in the background. The member never re-downloads anything.
Is a pkpass the same as a Google Wallet pass?
No, but they are equivalents. Apple Wallet uses signed pkpass files; Google Wallet creates passes through an issuer API. Issued from one design, both formats show the same membership data and update the same way, and each member receives the version their phone expects.