Moho Promo Codes & Coupons June 2026

Upgrade serial numbers for Moho aren't entered as promo codes in the discount field—they go in a dedicated serial validation field during checkout on moho.lostmarble.com. Users often see "Invalid serial" errors because they paste full serials directly into the promo box, which Moho rejects since that field is for coupon codes only.

Moho's checkout on the official site separates promo codes from upgrade serials, which auto-populate upgrade pricing after validation. A common scenario: Pro 13 users upgrading to Pro 14 enter serials in the wrong field during sales, hitting "Serial not recognized" errors if dashes are missing or the serial has expired.

To fix this:

1. Log into your Lost Marble account at moho.lostmarble.com with your old serial registered.
2. Select the Pro 14 upgrade product.
3. At checkout, find the "Enter Upgrade Serial" or "Validate License" field below the promo code box—paste your serial exactly as issued, including dashes (e.g., ABCDE-FGHIJ-KLMNO).
4. Click Validate; the discount applies instantly if you're eligible.

Keep in mind that this only works for official prior versions (e.g., Pro 13 to Pro 14). Serials purchased through third-party resellers may not validate here, and each serial is limited to one upgrade.

Pro tip: Register your old serial in your Moho account before starting checkout—this avoids "unlinked license" errors and saves time, especially during peak promo periods.

This is expected behavior at Moho—promo codes apply to the base price before tax, and location-based taxes or payment processing fees are added at the final review step. Users report seeing this on moho.lostmarble.com, where a discounted price in the cart can increase noticeably once taxes and fees are calculated at checkout.

Moho follows standard software retail practice: discounts reduce the base price, but US state sales tax or international VAT (which can reach 20%) is applied afterward. PayPal may also add a small processing fee depending on your region.

To work through this smoothly:

1. Apply your promo code in the discount field and confirm the reduced price in your cart summary.
2. Proceed to checkout and review the tax breakdown before completing payment.
3. If the final total looks incorrect, take a screenshot of your order summary.
4. Contact Moho support at moho.lostmarble.com with your screenshot—they can clarify charges or assist with billing errors.

Note that promo codes are typically single-use and apply only to the base product price on the official site. Taxes and fees are not discountable.

Pro tip: Use a desktop browser on the official Moho site to get the clearest view of your order breakdown before proceeding to payment—this helps you spot any tax additions before you reach the PayPal screen.

If your Moho Pro 13 serial isn't being accepted for an upgrade discount, the issue is most often a registration mismatch rather than an expired or invalid serial. Moho requires that upgrade-eligible serials be linked to an active Lost Marble account, and errors like "Serial ineligible for upgrade" are commonly reported when that link isn't in place.

To resolve this:

1. Log into your account at moho.lostmarble.com and check whether your Pro 13 serial appears in your dashboard.
2. If it's missing, email Moho support with your original purchase receipt or PDF serial documentation and request a "Pro 14 upgrade eligibility check."
3. Once confirmed, return to checkout and enter the validated serial in the upgrade field, including all dashes.
4. If your serial is still denied, you may have reached the perpetual license upgrade limit—in that case, consider purchasing at full price or checking whether an education discount applies to you.

Upgrade pricing is generally available at a significant discount within the first year of your prior purchase. After that window, a paid upgrade path may be required.

Pro tip: Have your original purchase confirmation email ready before contacting support—providing proof of purchase upfront speeds up the eligibility review and helps you take advantage of any active limited-time upgrade offers.