This content originally appeared in the MSE weekly email on 19 August 2015.

Two million people are about to be sent letters telling them they're entitled to money back on past card protection plans they paid for that were virtually worthless. Sadly, many will bin theirs thinking it's spam, and miss out.

This isn't the only case where you may be due wrongly taken money. Scan through my checklist to see if you're owed £1,000s. Don't waste 30% using claims firms, they're all easy to DO YOURSELF FOR FREE. Please email us successes.

1. Watch out for a Sentinel letter from AI Scheme Limited – over £100m could be repaid. 

Two million people who bought virtually worthless card protection (usually branded Sentinel) from banks are about to be contacted as part of a mass redress scheme. 

It started sending letters this week and will continue to until mid-September. Most people will receive £25-£250. When you get one we've full help (including if you've moved) and free templates to fill it in in our Sentinel (AI Scheme) redress help guide.

2. Warning. A deadline on PPI claims may be imposed – DON'T WAIT. 

There are worrying rumours suggesting the regulator may agree to impose a time bar to help banks. MSE and Which? have written a joint protest letter to the FCA to fight this, but if there's a chance you're owed, check now, don't delay. Full help, FAQs, how to check and templates in Reclaim PPI For Free.

Don't think "it's not me". Many had PPI added even after refusing it. Chick emailed: "Never thought I'd be entitled to reclaim PPI, but I wrote to my old card provider and received £1,467." It can be huge, as Tina found: "Got £75,000 refunded on three credit cards. Did it myself. No problem thanks to you."

3. Anyone who's switched energy in the last five years may be due hidden £100s. 

If you were in credit when you left, many energy firms effectively operate a 'don't ask, don't get' policy – and most people don't ask. Yet you can still get it back now. See how in Reclaim Energy Bill Credit.

Normally this is £100s but as forumite Col. Escargot found: "I saw your info about gas companies holding onto overpaid money. I'd switched from EDF 17 months ago. Got round to checking and the balance owing to was... £1,364. A brilliant result. I'd urge everyone to do the same."

4. If you paid for Experian's CreditExpert you could be due £100s.

We think it unfairly sold 'ID fraud expenses insurance' as part of these expensive plans, and people who follow our Experian CreditExpert Reclaiming tips are getting £100s back, including Valerie: "Read your guide, filled in the template letters and today we've just been refunded £210, no questions asked. Thank you."

Martin Lewis
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5. Flight delayed 3+ hours anytime since 2009? Get up to £420/person back. 

If you flew to or from the UK or EU and it was the airline's fault, you may be entitled to up to £420 back regardless of the flight cost. Full help, including our free reclaim tool, in Flight Delay Compensation. Jordan emailed: "Ta. Claimed £2,565 from Thomas Cook for a flight four years ago for a group of nine."

PS: While most of the other points here are about reclaiming cash wrongly taken, this is about compensation for nightmare delays. I'm wary of a compensation culture so read my legal vs moral concerns first.

6. Car damaged by a pothole that should've been fixed? You can claim. 

If you crock your car or bike on a pothole you may be able to claim for repairs from whoever controls the road – see our Pothole Claims guide. David said: "I hit a pothole on the M20 and suffered a cut to a tyre. I claimed from the Highways Agency and got £530."

7. If you're one of millions who pay (paid) monthly bank fees, check if you're due £1,000s back. 

If you got a packaged bank account (where you pay a monthly fee for extras such as 'free' travel insurance) because the bank upgraded you, upsold you, or said there was no choice but to get one, you may have been mis-sold. Free help in Reclaim Unfair Bank Account Fees.

Cath emailed: "I used the template letter on your website and received just over £2,500. I had been told I could only have an overdraft if I had a packaged account, and I never used any of the benefits."

11 ways to check if you're due £1,000s
Check if you're due £1,000s

8. Check 'n' challenge your council tax band for backdated £1,000s. 

Up to 400,000 homes in England and Scotland are in the wrong band. If you think yours is too high, follow my Council Tax Rebanding Check and Challenge System, and get it lowered and a backdated payout from when you moved in. 

I've had huge success with this since I launched it eight years ago, as Michael emailed: "I got my council tax banding reduced, saving me about £100 a year from now on, plus I got a £1,200 refund."

9. Bank charges reclaiming isn't dead - some can still reclaim £100s. 

Go beyond your overdraft limit and you can face hefty charges. If these caused financial hardship, you may still be able to reclaim. Step-by-step help and, of course, free template letters in Reclaim Bank Charges For Free.

As Scott emailed last month: "After an initial conversation the bank said I was not due anything, despite being stuck in an overdraft cycle. I then used the information on MSE and was offered £576. Thank you."

10. If you wear (wore) a uniform to work you could be entitled to a tax rebate.

If you wear a branded T-shirt, overalls or a uniform for work (not pleasure), you don't wear it elsewhere and you wash it yourself, you may be entitled to a tax rebate, possibly going back up to four years. Full help and how to do it for free in our Uniform Tax Rebates guide.

Forumite Butterflylegs said: "I just wanted to thank Martin. I applied for a uniform tax refund for the last three years and I've just received £180."

11. Millions of people are due money back due to tax code errors. 

Each year, millions of errors in the income tax system mean you could be overpaying. It only takes five minutes to check with our free Tax Code Checker and you could expect £100s back, Nina emailed: "I found the taxman owed me £1,300 and I'll be £160 a month better off. Thanks for making me check."