Short answer: There is no point at which books become unfixable. We routinely take on businesses that are 6, 12, and even 24 months behind. What gets worse with time is not the difficulty of the cleanup — it is what the delay costs you everywhere else.
The work itself scales predictably. A year of unreconciled transactions is roughly twice the work of six months. Bank feeds only reach back so far, so older periods mean pulling statements manually, but that is tedious rather than impossible. Nothing is lost permanently as long as the bank records exist.
What does get more expensive is everything downstream. A late or estimated tax return often means paying more than you owed, because nobody could find the deductions. A loan or line of credit stalls, because no lender will underwrite on books you cannot produce. Payroll and sales tax filings that were based on bad numbers may need amending. And the longer it sits, the more the not-knowing costs you in decisions you did not make because you could not see the numbers.
There is also a quieter cost, and it is the one we hear about most on first calls: the dread. Owners avoid opening the file, which means they avoid the whole subject, which means it grows. Almost everyone who finally calls says some version of I should have done this a year ago.
So the honest answer to “is it too late” is no. It is never too late, and you will not get a lecture about how long it has been. Bring us whatever exists — even if that is a shoebox and a bank login — and we will tell you what it takes to get current.
Related: How long does QuickBooks cleanup take? · What do I need to give a new bookkeeper to get started? · Cleanup & Catch-Up