It may be true, and it may not. Either way the honest answer takes a conversation about your position rather than a promise made before anyone has looked at anything.
Three different things arrive dressed as this complaint.
Sometimes the tax is simply higher than expected because the business did better, and nobody explained that in advance. That is a communication failure rather than a tax one, and it is the most common of the three.
Sometimes reliefs are being missed. Capital allowances not claimed properly, a director's remuneration mix that has not been revisited since the rules changed, pension contributions not used, a spouse's allowances sitting unused, or a business that would qualify for research and development relief and has never looked.
And sometimes the tax is correct, unavoidable, and simply larger than anyone wants. An honest adviser will tell you when that is the case rather than implying there is something clever left undone.
Look at the actual position before saying anything about it. That means the last two years of accounts and returns, the remuneration structure, what has been claimed and what has not, and what is planned for the coming year.
Most of what genuinely reduces a tax bill is timing, and timing only works before the year end. Pension contributions, capital spending, the salary and dividend split, the decision to accelerate or defer income — all of them are decisions, and all of them stop being available on the day the year closes.
What we will not do is promise a saving before we have looked. If the answer turns out to be that the tax is right, we will say so, and you will at least stop wondering.
Tell us what is going on and we will tell you what we would do about it. If the answer is that you should stay where you are, we will say that too.