monero-docs/docs/public-address/Integrated-Address.md

Integrated address

Monero integrated address embeds a compact payment ID.

Monero integrated address obsoletes the former practice of using full 32-bytes payment ID in a transaction extra field (where it was not encrypted).

Data structure (src):

Index	Size in bytes	Description
0	1	identifies the network and address type; 19 - main chain; 54 - test chain
1	32	public spend key
33	32	public view key
65	8	compact payment ID - 8 bytes randomly generated by the recipient; note that it does not need encryption in the address itself but it is hidden in a transaction paying to integrated address to prevent linking payment with the address by external observers
73	4	checksum (Keccak-f[1600] hash of the previous 73 bytes, trimmed to first 4 bytes)

It totals to 78 bytes. The bytes are then encoded (src) in Monero specific Base58 format, resulting in a 106 chars long string. Example integrated address:

4LL9oSLmtpccfufTMvppY6JwXNouMBzSkbLYfpAV5Usx3skxNgYeYTRj5UzqtReoS44qo9mtmXCqY45DJ852K5Jv2bYXZKKQePHES9khPK

Reference:

• question on StackExchenge