Both Direct Line and Virgin, two of the most popular providers, are open for business all day on Saturday 5 April, so customers can hand in completed application forms and cheques right up until the last minute.
Direct Line is setting up "PEP desks" at its regional offices to take application forms and cheques, while Virgin is likely to do the same, at least in London.
But to be safe it makes sense to make the call today or tomorrow, then fill in the form as soon as it arrives and send it off with your cheque no later than next weekend.
The other kind of long-term saving where the end of the tax year matters is a personal pension. If you are not in a company scheme, think hard about putting spare cash into a pension plan of your own - the Inland Revenue rules allow you to make contributions for up to six previous years.
Buying a pension is more complicated than putting money into a PEP, but companies such as Scottish Widows and Merchant Investors will explain the details on the telephone. But, as with all company representatives, they will only tell you about their own products.
Although you can only put pounds 6,000 in a general PEP for each tax year, many people are investing both their current year's allowance and next year's, says Robert Allen, PEP manager at Direct Line.
This was echoed by Tony Wood, marketing director at Virgin, which is taking in PEP investments of about pounds 10m a day: "Some people are investing a lump sum for this year and an initial payment for 1997/98, but the vast majority who are investing for both years are sending the full pounds 12,000."
Most of the big sellers, including those from Virgin, Direct Line and Legal & General, are tracker funds, which seek to match the performance of a stock market index by investing in all its shares or in a representative sample.
It's a simple idea which saves the huge amounts of money spent on active management. The downside, of course, is if the stock market does not do well, neither will your PEP. But it is important to remember that PEPs are long-term investments, so you should try to keep them for at least five years.
Most trackers follow the FTSE 100 or the FTSE All Share. The FTSE 100 covers the 100 top companies (those with the highest market capitalisation). The All Share covers about 900 - and its supporters point out that it includes smaller companies which often produce better profits growth.
Funds which track the FTSE 100 are offered by General Accident, HSBC, Fidelity, Midland, Sovereign and Virgin Direct, while Equitable Life, Direct Line, Kleinwort Benson, Gartmore, Old Mutual, Morgan Grenfell, Legal & General, HSBC and Norwich Union track the All Share.
An alternative to the direct sellers is the telephone-based brokers, such as PEP Direct and the PEP Shop, which offer plans from many big providers - often more cheaply than you could buy them directly. But it's even more essential to act early to meet the deadline.
If you are planning to invest in a PEP through a broker or an independent financial adviser, don't leave it too late. Make sure the intermediary has both the completed application forms and your cheque by Friday next - allowing a clear week for onward delivery.
The Independent has produced a free 32-page Guide to PEPs, sponsored by General Accident, a leading life insurance company. Call 0500 125888, or send your name, address and postcode (no stamp required) to Independent/GA Life, FREEPOST, Y0550, York, Y01 1BR.Reuse content