The Post Office will pay the rate of inflation as measured by the retail Prices Index (RPI) in April each year plus 1.5 percentage points on top.
Its bond requires a minimum of £500. Returns are calculated annually but paid at maturity in 2016.
Interest is not compounded and no additional deposits can be added. Penalties apply if it is cashed in early.
The bond is on sale until April 27 but could be withdrawn earlier if it is oversubscribed.
Yorkshire Building Society's Protected Capital account (PCA) Inflation-Linked Plan 1 pays income yearly, based on inflation over the 12-month period plus 0.1 of a point.
PCA2 pays out the change in RPI over the five-year investment term plus 1.5 points on maturity.
The minimum investment is £3,000 and the maximum £85,000. Yorkshire's bonds can also be put inside an Isa up to the maximum £5,100 allowance, plus savers can transfer £5,100 from an existing cash Isa.
Last month BM savings, part of Lloyds Banking Group, launched a five-year bond that pays a quarter of a point a year above inflation.
Louise Holmes of data compiler Moneyfacts says: 'The products are competitive when inflation rises, but there is risk involved. The Bank of England has said it expects inflation to fall in the next few years.'
Dan Hyde, savings correspondent at This is Money, says: Inflation has spooked savers this year. It's a grating concern, running at double the Government's target. With the official measure at 4%, savers need to find an account paying 5% before tax to beat it.
Outside of a tax-free Isa, that's impossible. The best around is a 4.8% offer from Aldermore Bank, launched last week.
That's where these inflation linked bonds become interesting. In essence, they help you maintain the spending power of your cash while it's at the bank.
But don't get too excited, there are a number of downfalls to these products. Providers such as the Post Office and Yorkshire Building Society are beginning to play on our fears that inflation is sticky. The fact that an 'inflation-linked' bandwaggon seems to have arrived is a clear warning sign.
The main issue is locking your cash into these deals for five years. As Louise Holmes says, inflation may well fall back at the end of this year. If it does, then savers might see their returns fall from a very tempting 6%-7% a year now to something like 3% or 4%. Compare that to Aldermore's 4.8% fix, and the risk is clear: you could end up worse off in 2016 if inflation fears recede.
Given the Bank of England's poor prediction record in recent times, I wouldn't bet on inflation falling, though - it's very hard to predict. But that's just the point: inflation-linked bonds are a gamble.
The key, as always, is to avoid putting all your eggs in one basket. If you think inflation is going to stay high, this could be a good opportunity to take advantage with some of your cash. If you're unsure or rely on savings income, then stick to more certain returns.
Kevin Mountford, a savings expert moneysupermarket.com, offers this piece of wisdom from within the industry: 'As with most products, the devil is in the detail and although inflation is currently high, the benefits will only be in the short term. A lot can happen in five years, so consumers need to be aware that the savings landscape may change considerably over this period.
