Boyfriend's birthday, most boys don't care much about such a day, but it is a trust that he will give it to you. Prepare well and make it an unforgettable birthday for him. Here are some suggestions for you:
First, in the form of a banquet, you can invite his friends to celebrate his birthday together. If there are many friends together, he will be very happy, but the cost will be a little higher.
Second, it is your private banquet. You can book a slightly more romantic restaurant and celebrate his birthday alone. I believe such a birthday will make him unforgettable.
Third, there must be a gift for his birthday. You can give him a small gift he likes. A watch or a belt are good. You can also give a creative gift. A box of DIY chocolates is very good, or your couple's color-changing cups, I believe he will love it.