Reduction of limit

born_again

OP, has not said how close to the limit they have been getting each month.

So it could be if not getting anywhere near the 7K limit, that they have decided to reduce their exposure to debt risk. Remember these companies will from time to time review credit limits & also look at customers available debt to income ratio. 
If it is too high, then they may take the action seen here.

cymruchris

sachalegge said:

My paperless statement arrived in February advising me I had broken my agreement and I had to pay a default charge, my credit limit was now £600

This is one of the key points the OP has made in that they were told via statement that they'd broken their agreement - so was this because a payment that was sent didn't arrive, was late, or wasn't sufficient? Or was it from going over the new £600 limit? Once the OP is back from holidays they'll no doubt have a clearer answer as to whether it was anything they did, like be late with a payment, that caused it, or whether it's a generic 'we've reviewed your credit history and have decided to reduce your limit for more details go check your credit reference reports'. It's possible the OP has other credit facilities that are close to the limit, or there are other negative markers that have influenced the limit reduction - either way, we'll need the OP to come back and expand on things a little more to understand the potential cause.

zagfles

grumbler said:

zagfles said:

grumbler said:

sachalegge said:

Can they do this?

No, they can't. Check the T&C. I'm sure they say that they must give you a notice well in advance. If there was no any notice, then it's them who broke the agreement, not you.

Why do you think they have to give notice in advance? That would be ridiculous, if they're reducing the limit eg because they're worried about the customer's creditworthiness or ability to pay, they're not going to give them 30 days notice so the customer can max it out before reducing the limit

They can block transactions taking the card over the new limit if they wish

Look at any card's T&Cs and I'd wager you can't find any that state they must give notice of a reduction in credit limit.

How much? I lay.

We’ll tell you what your credit limit is when we first open your account. We’ll then review it from time to time. If we change your credit limit, we’ll write to let you know.

https://www.barclaycard.co.uk/content/dam/barclaycard/documents/personal/existing-customers/terms-and-conditions-barclaycard-core-2020.pdf

Exactly - no advance notice, they tell you after they've done it.