Start from the assumption that you should not. A defined benefit scheme is a promise of an inflation-linked income for life, and giving it up cannot be undone.
A final salary pension pays a known income for the rest of your life, usually rising with inflation, whatever the markets do and however long you live. It normally keeps paying your husband or wife at a reduced rate after you die. The scheme carries the risk that investments fall and the risk that you live to 100.
Transferring converts that into a pot of money. The pot may look large next to the annual income it replaces, which is what makes transfers tempting, but from the day it moves the risk is yours: that markets fall, that you live longer than the plan assumed, or that you draw too much early on.
A transfer occasionally turns out to be right, and it is always for the same reason. The guaranteed income is worth less to you, specifically, than the headline figure suggests.
Transferring out of a defined benefit scheme is unlikely to be in the best interests of most people. Any recommendation depends on a full assessment of your circumstances.
The cash equivalent transfer value: the lump sum the scheme will pay into a personal arrangement, in place of the income it promised. Quotes are usually guaranteed for three months, and a large figure is not by itself a reason to take it.
Most unfunded public sector schemes — NHS, teachers, civil service, armed forces — cannot be transferred out to a defined contribution arrangement at all. The funded ones, such as the Local Government Pension Scheme, can be, and the same caution applies.
The Pension Protection Fund exists for that, and provides compensation subject to its own rules and caps. It is worth understanding your position, and is not by itself a reason to transfer.
Many schemes let you exchange some pension for a tax-free lump sum at retirement without transferring anywhere. The rate at which they do it varies a lot between schemes. Check what yours offers before you assume a transfer is the only way to get a lump sum.
If a transfer is worth examining in your case, you will see the workings, including what you would be giving up in pounds a year.
Tell us what is on your mind: a pension you have lost track of, a fixed rate ending, a will you keep meaning to write. We will tell you honestly whether we can help.