Unlike a lot of government efforts to ‘nudge’ people to behave in a certain way, be it using positive rewards (eg tax benefits) or negative penalties (eg fines, imprisonment), the recent changes to individual saving accounts (ISAs) has triggered the desired effect.

The UK Government’s plan to get people investing in Isas is working with CoreData’s latest research on the matter revealing flows into these tax efficient vehicles set to swell by as much as 67% in the 2014/15 tax year.

If the number of subscribers’ remains constant from past figures (ie there isn’t a rush to close accounts), the total market for cash Isas will increase by 87.1%, from £38.8bn to £72.6bn for the 2014/2015 season, according to CoreData’s latest report – Isa Season 2015: Buyer Behaviour and Distribution.

The increase in the flow of funds into stock and shares Isas will amount to approximately £4.4bn, or a 23.4% rise from £18.4bn to £22.8bn. This means total Isa sales are set to rise from £57.2bn in the 2013/14 season to £95.4bn this year – a 66.7% increase!

The industry can expect an increase of 21.6% in the average stocks and shares Isa investment, from £6,163 to £7,496. Average investment into cash Isas is set to rise by a staggering 74% to £6,413 from £3,704 last year.

From July 1, 2014, the new Isa or “Nisa” came into effect allowing savers to shelter up to £15,000 from tax authorities (something HSBC has struggled to do according to the news this week…) and representing a 30% increase from the previous limit of £11,520.

In addition to the limit being increased, the rules were also amended so all of the allowance can now be allocated to cash Isa, something which was restricted to half the allowance in the previous model. This means investors can now place the whole £15,000 into a cash Isa, this figure stood at £5,760 for the 2013/14 Isa season.

Hargreaves Lansdown comes out on top as the most popular provider of access to stocks and shares Isas (28.7%), Fidelity (10.6%) and Halifax (4.4%) round off the top three. But with numbers set to rise across the board expect booming business across this market in the next few years.

Of those who will invest in an Isa this year, 22.6% will make use of the maximum allowance. Specifically, 6% will invest all of their allowance in a cash Isa while 3.5% will use a mixture of both cash and a stocks and shares vehicle. The other 13.1% will invest fully in a stocks and shares Isa.

But the big question that remains is what exactly is the best thing to do with this £15,000 allowance?

With interest rates so low the returns on a cash Isa are nominal but with FTSE 100 nearing all-time highs many experts also believe now is not the time to throw large amounts of money in to the market.

The likelihood is that income will continue to rule the roost – with UK, global and multi-asset income funds likely to the big winners.

Most people love routine and security – they will stick with what they know. The same cash Isa supplier and a very happy fund manager by the name of Neil Woodford. But don’t expect too many sad faces at Hargreaves Lansdown either!