When should I do a BSNL validity recharge

You should do a BSNL validity recharge before your current plan expires to keep your mobile number active and continue using services like calling and receiving calls. If your validity runs out, your services might stop working. Many BSNL plans offer different validities, like 30 days, 330 days, 365 days, or even more, so you can choose one that fits your needs. Regularly checking your plan's expiry date will help you know when it's time to recharge.