TOTO toilet tank lids can look deceptively similar, but a replacement should be matched by more than overall size. The safest identification starts with the toilet and tank model information, then uses measurements, shape, underside details and color as confirmation.
Start with the tank model number
On many TOTO two-piece toilets, the tank model number begins with ST. TOTO parts manuals often list a separate tank-lid service part number, frequently beginning with TCU. That means a number printed on the tank and a number molded into the lid may both be useful even when they are not identical.
Write down every number you can find inside the tank, on the back wall of the tank, and on the underside of the lid. Do not assume the largest number is automatically the lid number.
Use shape and dimensions to confirm the match
Measure the lid at its widest left-to-right point and its deepest front-to-back point. Then compare the front edge, rear corners, side taper, center crown and underside locating tabs. Two lids can share similar dimensions while having different corner geometry or underside seating points.
Color matters too
TOTO has sold toilets in multiple colors, including Cotton, Colonial White, Bone, Sedona Beige and darker finishes on certain models. A correct model in the wrong color can still look obviously mismatched in the bathroom.
Best identification checklist
- Tank model number
- Any number molded or stamped under the lid
- Overall width and depth
- Clear top and underside photos
- Flush type, especially on dual-flush models
- Toilet color
Browse our current TOTO toilet tank lids. Inventory changes frequently, so if the exact lid is not listed today, check back as new original lids are added.
If you do not know the model yet, start with our general toilet tank lid identification guide.