Budget against your lowest month, not your average month. The average is a planning number, not a spending number.

The IRS generally expects estimated tax payments if you will owe $1,000 or more, split across four payment periods.

HMRC's Budget Payment Plan lets you pay your next Self Assessment bill by weekly or monthly Direct Debit, and you can pause it for up to 6 months.

The CRA requires instalments when your net tax owing tops $3,000, or $1,800 in Quebec, in the current year and either of the two before it.

Read the full guide

pennyandplan.com