Matching tolerance

Tolerance exists because reality is untidy. Rounding, a wire or transfer fee, the rate applied to a foreign currency invoice, cents left over from a partial settlement, even a bank booking the item a day later: each of these can separate two records that describe the same event by a small amount or a couple of days. Without a tolerance those lines fall into the unmatched bucket and reach a person one by one. The iFinances matching engine carries a cents-level tolerance, and cross-currency comparisons are converted at the official buying rate published by the Central Bank of the Republic of Türkiye, so rate driven gaps are resolved by calculation rather than by widening a threshold. Lines that fall inside tolerance still arrive as a proposal with its reason written beside it: iFinances closes no line on its own, and the decision stays with a person.

Tolerance costs you in both directions. Set it too tight and correct matches are pushed into a manual review queue; as the queue grows the close takes longer and the team loses the time it should spend on real exceptions. Set it too wide and the engine produces false matches: two different invoices with similar amounts pair up, a genuine difference looks settled, and the error survives for months without drawing attention. Tolerance is therefore a written rule rather than a slider. Which amounts, which date windows and which currencies match at which threshold should be recorded, every match should carry its reason beside it, and the audit trail should let you trace the decision backwards.

The common misreading is that tolerance makes a difference disappear. It only decides that two lines describe the same transaction; the remaining amount still has to be posted somewhere, usually to exchange differences, bank charges or rounding. The second misreading is that a single threshold fits every line. In Türkiye, invoices subject to KDV tevkifatı, the partial VAT withholding regime in which the buyer pays part of the VAT directly to the tax authority instead of to the seller, are systematically settled below their invoice total. That is a rule to model, not a gap to absorb, and stretching the threshold to swallow it lets genuine errors through the same door.