WELLINGTON, Sept 20 - Seymour had the fake cash printed - with his own face on it - and took it to the NZEI's headquarters in Wellington on Wednesday in a wheelbarrow.
"Teachers have been underpaid for a very, very long time," he told reporters.
"We're offering to raise teacher pay by $20,000 on average and let schools and boards decide how much to pay their teachers."
Mr Seymour said there was a critical teacher shortage across New Zealand and something had to be done.
"Their maximum is $78,000 and everyone gets paid the same," he said.
"They need the opportunity to see what a billion bucks looks like."
Seymour wheeled the money into NZEI's reception and was told to leave it there, which he did.
NZEI president Lynda Stuart later said ACT was totally out of touch with what mattered to teachers.
"This is straight out of ACT's playbook - undermine public education, undermine teachers and undermine unions."
She did, however, acknowledge ACT's concerns about teacher pay.