Cheapest energy fix ending, urgent 5.17 % cash ISA, summer plants £12, £50 off Dyso n, free £175+

By Friday, use it or lose it...

The top easy-access cash ISA pays 5.17%, beating normal savings, so your money's nicer in an ISA. Yet do it NOW, the tax year end's imminent

Happy New (Tax) Year for Saturday, which means the year-end that matters is Friday 5 April - that's THIS FRIDAY - as the end of the tax year has a material impact on your life and pockets. For us though, the imminent focus is savers and the top cash ISAs.

Each tax year, every UK adult gets a £20,000 allowance where you can put money away as savings or investments to protect it from tax. Yet while the tax year ends on 5 April, in practice...

Don't leave this till Friday. Many firms shut applications days before, as they need processing time. So sort as soon as you read this (if not sooner).

If you don't use the year's allowance, you lose it on 5 April. You can't carry it over. Yet once it's in a cash ISA, it stays tax-free year after year, so some who have maxed it every year now have £100,000s in cash ISAs. That means you could put £20,000 in now and, if you have it, another £20,000 in on Saturday, the start of the new tax year.

Let's not over-complicate it, a cash ISA is just a savings account you can put up to £20,000 in per tax year where interest is NEVER taxed. Just like normal savings, they can be easy-access, notice accounts or fixed - because they are normal savings, just inside a tax wrapper.

How savings tax works...

Savings aren't taxed, but the interest on them is taxed as income. Yet each year you get a personal savings allowance (PSA), which means:

- Basic 20% rate taxpayers don't pay tax on the first £1,000/yr interest.
- Higher 40% rate taxpayers don't pay tax on the first £500/yr interest.
- Top 45% rate taxpayers pay tax on all interest (outside an ISA).

As interest rates have risen, you need far less saved to bust the limit. At 5% interest, a 20% rate taxpayer would earn enough to pay tax with £20,000 saved, a 40% rate taxpayer would earn enough to pay tax with £10,000 saved.

So if you've savings above that, then you want to protect them from tax, and that's where a cash ISA comes in, as ISA interest is NEVER TAXED, it doesn't count towards your personal savings allowance.

Right now, the top easy-access cash ISA beats top savings. This is unusual. Cash ISAs aren't normally a winner for savings that aren't taxed, so normally for those with lower amounts we say forget them and chase the rate. Not right now though, unless you want to fix (where normal savings win)...

Fixed cash ISA rates are lower, but they have one big perk. Unless you're paying tax on savings, you'll get more interest in a normal savings fix. Yet there your money is locked away without access. Cash ISAs can't lock savings away, even in fixes, so you can access your money (but normally lose 90 to 180 days' interest to do so).

So if you are pretty sure you can lock some money away, but there are risks that you may need access, a cash ISA fix has more flexibility.

Lifetime ISAs (LISAs) are the best currently available savings for anyone who hopes to one day buy their first home, as the state can add £1,000s to your deposit. Though there's a big but (more on that in a moment). To show you how big an impact they can have...

Steve emailed us: "We opened a Lifetime ISA each and deposited the max for three years running - with the Government bonus, we had £30,000 in total. Now we're in our first home and are considering starting our family, and we can't thank you enough for your help in getting us to this stage in our lives."

Five need-to-knows about free LISA money. LISAs are tax-free savings or investment accounts openable for those aged 18 to 39. While usable for retirement money, their best features are for first-time buyers:

i) You get a 25% bonus on everything you put in, up to £4,000 per tax year, till you're aged 50. So if you save £1,000, you'll have £1,250, or save the max £4,000 a year, you'll have £5,000. See LISA bonus details. Yet of course the deadline to get your money in is this Friday, and again you'll need to be quick.

ii) You can use it on your first residential home (costing up to £450,000). Those who have never owned/part-owned a home anywhere can use it to buy a property with a mortgage, as long as the LISA's been open at least a year.

iii) Withdraw before age 60, if you're not buying a qualifying home, and you pay a 6.25% penalty. So you'd get back less than you put in. See how LISA penalties work (& think carefully whether you'll definitely get a qualifying home).

iv) It's doable even if you're buying with someone who isn't a first-time buyer. It's an individual product, so first-time buyers can still use it, regardless of who they buy with. Equally, if both are first-time buyers, you can get one each.

v) Already got a Help to Buy ISA? These were LISAs' forerunners (and can't be opened now). You can have both, but can't get the first-timer's bonus on both, so see Help to Buy ISAs vs LISAs for which is best for your savings.

Most aged 18+ should put £1 in a LISA (if you haven't already). A LISA rule quirk means it needs to be open a year before you can use the bonus to buy a home. Nothing to do with the tax year - open one with £1 now just to start the clock, so you can use it at speed if you need it later (and if not, withdraw the £1 and suck up the 6p loss).

Top Lifetime ISAs (& boost your interest if you've already got one). With cash LISAs, it's all about maxing the interest. Our Top cash LISAs guide runs through top payers, including those that can be opened with £1 (there are also investment LISAs, more for those using LISAs for retirement). If you've an existing cash LISA, you can transfer to up the rate.

Up to £9,000 per tax year can be put into a Junior ISA for under-18s (or in their predecessor, Child Trust Funds). But again, that means the deadline is near. We wrote about this in last week's email, so if you don't mind, we'll just point you there. We've double-checked and all the products are still up to date. Yet go quick, the deadline is urgent.