UMA Addresses

The UMA address format is based on Lightning Addresses (LUD-16), and are themselves valid LNURL Lightning Addresses when the $ is stripped. They are in the format $<username>@<domainname> (eg. $alice@somevasp.com). Similar to Lightning Addresses (LUD-16), the domain will be used to make the first lnurlp call to somevasp.com.
UMA Address Diagram
  • Must start with a $ symbol. This is to differentiate from email addresses and clearly identify an uma address.
  • The <username> portion is limited to a-z0-9-_.+
  • Addresses are case-insensitive, but by convention are written only with lowercase letters
  • Like email addresses, the maximum number of characters for the <username> portion of the address is 64 characters (including the $).
The UMA SDK validates these requirements and will throw an error if they are not met.
UMA addresses are valid Lightning Addresses when the leading $ is stripped. Receiving VASPs who choose to support plain LNURL-PAY transactions (which is a subset of UMA) should treat an incoming LNURLP request to a receiver without a leading $ as a request to pay the receiver directly via LNURL-PAY. This way, users can still have a single user name compatible with both UMA and LNURL, while keeping a clear distinction between the two for cases where a VASP has to understand regulatory requirements.