A frugal life is an easy life!

"Actual loss" is a gauge for determining whether or not the fees, charges, termination costs or administration fees (and many more charges dressed up with fancy names) are what your personal circumstances have done to cause a loss to a business where a contract exists.

This maybe your mobile phone contract, your bank account, your credit agreement, etc.

I don't think any person can deny that if you have gone over drawn by £3, you have cost the bank £3 plus an amount for recovering that £3. This is "Actual loss" and should be paid willingly.
Problems arise when a bank charge is levied against your account for say £25 for going overdrawn.
The bank wants its £3 plus cost for an automated letter, an envelope, a stamp. Being generous this [in the real world] would generate a charge to your account of around £6 in total. So why the £25 charge?

Banks *I'm using banks as an example, it could in theory be any other industry claim continuously that it lists the charges applicable in it's terms and conditions. This is completely irrelevant!
Continuing to repeat the same question, "Is this charge actual loss?" results in at best, some very bizarre and obscure attempts to justify it without giving you a straight answer. This is because in almost every case, the charge not only recovers money for the amount of actual cost to the bank, but an additional amount, that has nothing to do with how you manage your account whatsoever.
As the charge issued against your account is not entirely for the bank's actual loss, caused by your management of your account, under common law in England and Wales [legal precedent dates back to the early 1900s] this is deemed to be "a penalty."
"Penalty charges" are unenforceable under common law (in England and Wales) - it really is that simple!

If I had a pound for everytime a telephone advisor reels off how "charges are listed in their terms and conditions" and "our charges are very competitive compared to every other company in that partcular industry" I would be a very rich man indeed.

The simple test whenever you are faced with a charge/fee, etc, is to ask continuously, "Is this charge/fee actual loss?"
Nine times out of ten, you will not receive a straight answer.
Don't be bothered by this, most of the time the telephone operators have not been trained to answer this question, or have been trained to answer it in a manner that won't allow for any comebacks or claims.
Occasionally, you will get an advisor who will concede over the phone that a charge/fee does not recover actual loss. These are rare occasions indeed, but joyous ones. First declare that you wish for what was said to be confirmed in writing (don't panic, it will never happen) so write to them and demand a written transcript of the call.
Once they play it back and their admission is heard, a "goodwill gesture" of the charge/fee reversal, will often come about as if by magic!

Failing that, the scope for further action becomes available.
If you decide to go via the small claims route, (that's a big if) it would be one of your "3 strikes against them" in that, can they appear before a district judge and prove that their charge is "actual loss"?
Hopefully, it will rarely if ever, come to this.
Continuous questioning of "is this charge an actual loss?" - along with, "Please provide a breakdown of the charge/fee in writing" - usually gives you good grounds for senior people within the company to waiver the charge/fee.

Remember, this is not avoidance of paying charges/admin fees, etc.
If these fees are actual loss then fair enough. That they are listed in terms and conditions is irrelevant, they must, under common law in England and Wales, be ONLY for "actual loss."
If they are not, then they are a "Penalty charge" and you are within your rights to stand your ground and demand that they are reversed.

Be strong, stand up for yourself!