Hello Graham-birks, Welcome to the Community. We've included a helpful article about limits in Quickbooks Online. In terms of transactions, there is no set limit. A high amount of transactions may cause some latency.

Hi,

I've just been told that 79,000 is too many transactions - so in other words the more you use Quickbooks then you will hit serious problems.

Some latency issues!! it takes over 45 seconds to match just one transaction!! I have 800 to do. Is your suggestion therefore to change to Xero?