TOKYO (Reuters) - Japan's national tax revenue for the last fiscal year that ended in March has been confirmed at 56.3 trillion yen ($553.75 billion), undershooting the government's earlier estimate as yen rises hurt corporate profits, government sources told Reuters.

Lower tax receipts will likely affect funding for the additional spending the government is planning to compile later this year to support the economy, which is struggling with weak domestic demand, a stronger yen and external risks such as Brexit.

In recent years the government has tapped bigger-than-expected tax revenues for financing extra stimulus budgets.

The confirmed tax revenue for last fiscal year compares with the earlier estimate of 56.4 trillion yen.

(Reporting by Takaya Yamaguchi; Writing by Tetsushi Kajimoto; Editing by Chang-Ran Kim)