Excess Roth Contributions

[Chief]

I know that there is a 6% excise tax on excess Roth Contributions. MJF is less than $150,000 for modified AGI .You can contibute up to 4,000 (5,000) if you are 50 or older.

Is there a limit on excess Roth contributions for couple filing joint as long as the 6 % excise tax is paid?
And is the excise tax paid each year the contributions are held?

[Bees Knees]

The 6% excise tax penalty applies to the excess contribution for each year the excess plus earnings is left in the account. There is no limit to the excess contribution, as the penalty increases according to the excess amount.

I suppose if someone thought they could make more than 6% every year on their investment, they could contribute a million dollars to a Roth IRA and pay the penalty each year, and then draw the excess out tax free after age 59 1/2, assuming they had a Roth IRA for at least 5 years. Although no Roth IRA custodian would allow such an excess amount being contributed in one year.