The five GST mistakes we see MSMEs make every month — and how to stop making them.

GST is unforgiving. A wrong percentage on a single invoice can cascade into reconciliation pain at month-end, mismatched 2A/2B reports, and last-minute panic before the 20th.

Here are the five mistakes we see most often, and what to do about each one.

1. Wrong GST rate applied to the wrong item. Atta and basmati rice don't have the same rate. Yet because it's faster to type, MSMEs default to a single rate for whole categories. Fix: Build a master item list with the correct GST rate stored once, and never type a rate by hand again.

2. New supplier added with wrong GSTIN. Manual entry means typos. A wrong GSTIN means the input credit doesn't match. Fix: Validate GSTIN format on entry, and verify against the GST portal once a quarter.

3. Same item in five different names. 'Sunflower Oil 5L', 'Sunflwr Oil 5ltr', 'SF Oil 5lt' — Tally treats them as three different items. Inventory reports become useless. Fix: One canonical name per item. Map supplier variations to it.

4. Reverse charge missed on freight or services. Easy to miss when you're typing fast at 10pm. Fix: Tag suppliers where reverse charge applies, and let the system flag invoices automatically.

5. Books reconciled only at month-end. By the time you find a mistake, the supplier has invoiced ten more times. Fix: Reconcile weekly. Daily if you can.

Do this consistently and your CA will stop calling you on the 18th.