400%2C000%20people%20with%20lit: "Between 2018 and 2020, almost 400,000 people earning less than £13,000 received a penalty for not filing a tax return on time. Very few of them had any tax to pay, given that the tax-free personal allowance was around £12,000. But, by failing to submit a tax return, they were fined at least £100, and often thousands of pounds. For most of those affected, the penalty represents more than half their weekly income."